Here's a thought:
Since it seems the original serial # has been messed with, but parts of it could have been copied over, I decided to look up OT 81552. This is an early 16 ' model, and should be fairly easily recognizable ... if it matches.
81552 is a 16' CS grade Double-ended boat built between Nov. 1923 and July 1924, and shipped on 9 Aug. 1924 to Hammond & Cooke, Monticello, NY. Made with Western cedar planking, open spruce gunwales, birch decks, seats and thwarts, it also had a keel, outside stems and floor racks as well as being equipped with rowlocks and a rudder. The original color was dark green.
Hope this may help. If it doesn't, then someone has been very creative in trying to make up something that looks like an OT number, as well as to disguise it.
I'll try to attach a scan of the build record which is folio 12623 in the 81000 series.
Best to all,
Roger