So your only interest in Platos model is if you can demonstrate some sort of compliance with what you have suggested for India...?
The chains in Timaeus'
Now, when all the stars which were necessary to the creation of time had attained a motion suitable to them,-and had become living creatures having bodies fastened by vital chains, and learnt their appointed task, moving in the motion of the diverse, which is diagonal, and passes through and is governed by the motion of the same, they revolved, some in a larger and some in a lesser orbit-those which had the lesser orbit revolving faster, and those which had the larger more slowly. Now by reason of the motion of the same, those which revolved fastest appeared to be overtaken by those which moved slower although they really overtook them; for the motion of the same made them all turn in a spiral
However. This does not mean that Plato would not utilise a different picture to describe a story.
That the Indian model is related to the flood tale that is 100% correct according to the extant texts...there is no debate here. The sequence of pole stars is involved with a sequence of destructions and creations according to this model and this is verified within the Indian texts. In fact this is replicated in Biblical texts although it is not so obvious there. The Biblical authors were pretty good with allegory and metaphor which makes it an interesting work to study.
So there is no doubt that the pole star sequence relates to flood and creations.
Why does Plato not mention any of that in his discourse on catastrophism...?
His pseudo-source is egyptian tradition with no mention of Pole stars.
The Atlantis tale is of a flood, a destruction. The dating given by Plato makes this roughly the middle of the period between pole stars Vega and Tau Hercules. If the circles of the Atlantis diagram are seen as replicating the circling of the stars of the constellation Hercules at that time Tau Hercules would be the centre, on the 'axis of the universe' as Plato describes the axis of Earth that takes in the positions of both the poles on Earth and the celestial pole stars. In this case the description of 'before [or beyond...dependent upon who's translation one refers to] the Pillars of Hercules' would be referring not to a place but to a time, a time before Tau Hercules was pole star. This once more would be correct regarding dating. This would compliment his '9000 years ago'.
This picture is that described in the Indian texts
Yes Plato is concerned with catastophism, but his own work states the stars were set into fixed positions and orbits and he demonstrates no awareness or interest in the effects of precession, understandably as this was after his time. Again there is not a single mention of any Pole star being linked to catastrophism, nor does he show any interest in Indian or Hebrew text and traditions...ostensibly only Egyptian.
The location involved would be somewhere where at that time there was flooding...flooding that was retained in folk memory. There is no evidence for any story of this nature that is dated to that period in the Mediterranean region. Yet Plato cited that era in history specifically and hence he must have been aware of something that had happened and was remembered.
The Greeks were aware that ancient cultures had existed along the Atlantic coastline and in Spain and North Africa as well as the Mediterranean islands, that had left behind monuments no longer understood, in trying to put together a larger picture of time and the rise and fall of civilizations it could perhaps have been conjectured that these were of a culture that had advanced so far Eastward before being erased from history.
In fact his dating for the earliest expansion of such cultures is fairly accurate, except that they expanded from the opposite direction with ragards to the Neolithic expansion.
The location involved would be somewhere where at that time there was flooding...flooding that was retained in folk memory. There is no evidence for any story of this nature that is dated to that period in the Mediterranean region. Yet Plato cited that era in history specifically and hence he must have been aware of something that had happened and was remembere
Plato wasn't really interested in a singular flood, but how such events are natural and regular, his Atlantis tale is an example of one such, after all his pseudo-source was Egypt which had a flood every year and no tradition of a singular flood...he was putting traditions such as the Greek flood into a greater and more natural context rather than a supernatural one determined by the Pole stars or some such, the very suggestion of which is anathema to his entire argument.
Plato made comment about a surrounding continent and other islands that effectively make little sense...The description does not fit anywhere known on Earth today never mind in Plato's time or even 9000 years before Plato. However, if seen in a cosmological context this does work. This is seen clearly in Chapter 14 of Deluge.
It only makes sense if the Pillars of Hercules as well as having a geographical context were also understood in terms of there mythological premise of being placed at the Western extremity of Atlas, the Western horizon, and that the continent before ultimate West was the Americas...and that these cradled the ocean of Atlas.
So possibly a rumour from some distant voyage of the Phonecians or some such.
Hence, my evaluation covers the description supplied by Plato in terms of time and place and the islands and surrounding continent. Indeed, as he claimed the Atlanteans were clever operators then even this fits the bill as the folks who moved out and into India and eventually kick started the Indian developments at Merhgarh and developed the measures. It merely means that for this specific tale he would have borrowed a description from India to tell a story about people who were Indian...I think that this is a very strong possibility. There had been plentiful contact with India for thousands of years by the time of Plato hence there is no problem with knowledge derived from that region.
To accept this version as plausible merely means accepting that he deviated from his own developed concept for the sake of a story about people in a different district at a different time...that he used their model to tell their story...a story of a flood...as indeed the same model was used to tell the story of the flood in their region...
Platos tale has nothing to do with India, his claimed source is Egyptian tradition, his setting the Western mediteranean and beyond...if you want to believe however the mythical Atlanteans were the founders of Indian culture i guess that's up to you.