These marks are not apostrophes. These are, imo, a cross-reference marks, indicating the change Vyse made to the (hitherto blank) disc in the Khufu cartouche at the bootom of this page of his journal.
Consdier all the other discs he has drawn on the page (see below):
Notice how they all are drawn with just a single outline with the exception of the disc in the cartouche at the bottom of the page--it has a double outline as it is a 'compsite'; a hatched disc within what was a plain disc (just like the one top-right which he claims also to have come from campbell's Chamber--hence a contradiction as there is only one Khufu cartocuhe in Campbell's Chamber).
You can also see the X's above the blank discs, just outside the cartouches. Vyse realises the blank discs are wrong and require to have the three hatched lines.