I have a 1932 "Light Weight" model with slimmed forearm and no horseshoe. 26-1/2 in barrels, Mod and IC, no rib (striped matting down the barrel), normal double triggers, with the O and U marked on the tang, however, at customer's request, the firing order was reversed, so the front trigger fires the upper barrel.
#3281C has a "C" in the number, but Mr Jensen does not know why. The opening lever has a very nice script and intertwined FN on it. It has the Gold S and is 24k gold according to Mr Jensen. It does have modest engraving, unusual for pre-war grade 1s.
Here is my gun's serial number in the original FN record book at the Browning Custom Shop in Liege, Belgium. I toured it last yr.
Here is the C, the FN, and the gold S:
And this is my favorite upland gun; I have some minor wood cracks to repair, then I will hunt with it some more.