Originally Posted by HelpSingularity

vmizera
If your 1982 Trek 720 came with 27 inch rims then it probably is not a 1982 model. The 1982 models came with 700c rims, as well as center-pull brakes. The 83-85 models came with 27 inch rims and cantilever brakes. If your Trek 720 has center-pull brakes then it is a 1982 model. Cantilever brakes and it is a 83 to 85 model.
And not to get too deep into the weeds but for 1982, and only 1982 Trek called the complete bike the 728. The same bare frameset, was called the 720.

This is all spelled out in the 1982 Trek catalog that formerly resided in vintage-trek.com (RIP)
Time to get off my soapbox.