OK.
On the downside, it does not appear that the lathe has been used in the past 50 odd years. The bed surfaces have not been oiled in at least that length of time. My guess is that someone who needed some parts to complete another 101.21400 or Atlas 618 might be willing to give about $100 for it complete.
Parts obviously missing from the photograph are the tailstock ram, at least part of the ram locking mechanism, the set of three outside jaws and the chuck key for the chuck, and about a dozen additional change gears. Also the tool post, two 1MT Dead Centers and a 2MT to 1MT adapter. I can't tell much about the stand that is is bolted to.
As I wrote earlier, the $25 donation would allow you to list it in the For Sale area but I cannot actually give you any odds on what sort of response an ad there would draw. The donation would also give you access to our Downloads section where you would find PDF scans of the original owners and parts manual.
Before listing it for sale as a nearly complete lathe, you will have to partially disassemble, clean and oil it. If you decide to do that, you should also search for the missing parts, using the parts manual for reference.