[Lynn Eades]

If I have read the parts book book correctly (1941 MkI*book), they should be 2BA.
Although the MkII* is later, I think they would have stuck with the same threads. I don't actually know.
The following might help?
2BA is not the same as 10-32 but it is sort of close.
2BA is about 0.182 dia. (these are actual measurements on screws, not from a reference book)
10-32 is about 0.189 dia.
Over about 4 threads one will NEARLY lay into the other
Reality is they don't fit and I can imagine that what probably happens is that they go tight in the thread before the head takes up any real clamping load.(this will depend on how good a condition the thread is in)
If you can't locate the 2BA screws then maybe tapping to 10-32 is an answer.
Keep in mind that the screws go into a blind hole in most tanks, so a plug (bottom) tap is in order.
The holes are blind because the mounting ring is welded to the top of the tank after the ring is made.