Many Q's Aaron. Campy seat post? stamped 27?
I wasn't sure for mine as it had a stove pipe in it. Got a 27.2 and it fit. My 531 decal says 3 main tubes, FWIW.

Are those Balilla brakes? Interesting. Mine came with Uni 61's

Is the triple crank 144 BCD? 151? Did they have triple record cranks back then?

I dig the 3TTT bar and stem. Could be original, as I think Avenia and others built these up from frames.

What kind of rims? No Record hubs?

Oil nipple on the BB as well?

And, lastly, surprised the owner got what looks like a Campy seat post binder bolt to hold on that QR brake bracket.

Super cool bike. I like the colors.