I happened to see a photo of a WWII Arisakaicon scope base recently. The similarity to the PPCo. mount design was rather striking. The difference of course was the adjustable, ie: collimatable and zero-able rings on the Arisaka.

If these PPCo. scopes were in fact truly collimated, presumably they were set up in a jig similar to that used for the No.4(T) conversions and the body sides machined to suit.

Or does that odd reference in your manual cited elsewhere Roger to the impracticality of zeroing for windage beyond 100 yards suggest it was all a bit more vague on the PPCo. setups?