Publicly traded partnership? You (someone) should be maintaining a basis schedule for the partnership investment. In my experience, if the units were bought and sold through a broker (as opposed to transferred around, inherited, etc), the PTP sales schedule is correct.

I enter a Sch D transaction for the 751 gain with basis = proceeds and accumulated depreciation equal to both of them (and adjusted AMT accumulated depreciation to make the AMT adjustment right), but anything that gets you to Part II of the 4797 is good enough.

I think lots of people enter it in the K-1 input screen under Line 11 as "Ordinary gain to be reported on 4797 Line 10." I find that the "From K-1" memo that produces, and the presentation on the basis schedule, to make it harder for me to tie out more complex returns, but for a straightforward return, it's quick and easy.