Update-
found some clamps on here via my WTB!

Regarding the frame, I researched more into 531 and the history of their decals. Interesting stuff. This bike is kind of a puzzler as to why it would have the three tube decal but it also has original 531 fork decals. Does the three tube designation just imply only three tubes are butted or only three are 531?
Also, the frame itself has a Campagnolo record sticker under the saddle that looks original. I guess vintage bikes were more made to order than I thought.
Lastly, what in the world are these clamps near the stem for?