it is humbling to see you have been looking at this since 1995 and before.
You know i won't let go!! 897.60 is not my number it is Thom's and also confirmed by Mike Parker Pearso in his academic paper'Units of Measurement in Late Neolithic Southern Britain' i may have mis quoted this is from memory.
897,60 is an amazing number and i feel sure your calculations are fine.
Somethimes decimals do give a diffent perspective than fractions but it has to work in fractions.
The pi solution in Rind 50 is 4x4x4x4/3x3x3x3 so beyond the cube.
this is 1.333r x 1.333r x1.333r x 1.333r = 256/81
1.333 x 1.333 = 1.777r
So pi is the square of 1.7777r and this is 1.6 x 1.111r the UOIO.
I alwya relate these numbers to he monuments and this is the greater cursus 7 units split east to west as 4 to 3.
When i used to post on the megalithic portal,
I devised a test called the Aubrey circle test. If you discover an anciant unit you divided it into 897.60. If it produces a rational number you are in business.
eg the Roman foot as 0.971428571 gives 924 so Macaulay was cooking with gas.
eg Sivertsen's unit 1,056 the long foot 897.60 / 1.056 = 850 so Harry is definitely not barking up the wrong tree but he is treading on Thom's toes as 850 x 3.2 is 1000 of AT's megalithic feet.