I have a new to me Windsor Proesional. It has 236 stamped in the seat lug. Any ideas what the number represents ? Included with the frame was the original Campagnolo seat post that is only 13cm long. I have never seen such a stubby seat post. Is that a common length? Thanks

As far as the seat post goes, it was probably cut down to save weight.

Possibly, though Campagnolo made 2 lengths; the normal, and a much shorter one. I'd guess the normal would've been original, but, who knows?