[Leica] filter size for 90/4 Elmar LTM ser no. 874068

[Jeffery Smith]

My 90/4 Elmar LTM needs a lens hood, and I've already bought two that are too large. I've been sort of winging it poring over forums where the lens is being discussed, but there are apparently a lot of different 90/4 Elmars out there. This  is the lens:
https://www.ebay.com/itm/144090296987 <https://www.ebay.com/itm/144090296987>

Anyone have any idea what the filter size for this lens is? I have all of Erwin Puts' books, but they are all in Louisiana at the moment.

Jeffery