Verito 22 1/4 inch Extension Lens Serial Numbers?

Just picked up a scruffy early style Verito with just the 22 1/4" front cell. I notice on the back of the cell near the threads there is a hand written number in the 36,000 range. If Wollensak assigned these extension lenses serial numbers in the Anastigmat serial number range, that would be about right for this style of barrel & font. 1916.

Anyone else have a serial number written on the back of their Verito Extension Lens?

I have two, and a close inspection revealed no serial numbers or other markings on the rear.

Attachment 206585

You can just make out the 37xxx number. Hmmm. These extension lenses were introduced in 1922, so now I don't have any idea what this number might relate to.

Very interesting indeed. I just checked mine and no numbers.