Crystal Size of a 50's Jumbo

I recently helped this 50's 38mm 2505 to face-plant on a tile floor, cracking the crystal and dislocating her arms in the process.

I'd like to source an OEM replacement, and wanted to get a step ahead of my watchmaker if possible and order the right one for installation. I know he is right that it's extremely difficult to accurately size a cased crystal because I get a different damn measurement almost every time. That is why he wants me to wait until he can look at it...but for "reasons"...I can't.

So 33.6 mm is the diameter I tend to land on when measuring with my caliper. And that looks like a known / plausible size.

Anyone disagree 33.6 would be the right fit? Any comments or tips or things to be aware of as I go about the project of sourcing one? Should I expect an OEM to be signed in the same way Speedmasters are? TIA.

obligatory photo...

Hi,
Reference 2505 has different case sizes and different glass ring widths. The crystal sizes vary from 338 to 342.

Thanks @Temprus – would knowing the case size be determinant? It's roughly 38mm not including the crown, of course...

(and when I say "roughly" I mean exactly, but with the caveat that it's me wielding the caliper)