If it takes the modern mags, that's the biggest obstacle already overcome.
The price may be hair high if the finish is rough.
The pin-hole in the safety says its the old style safety, and you must stick something in that hole to retain the internal spring if you ever remove the safety. Otherwise you'll have a heckuva time getting it all back together.
Pre-Bs are nice, but they're not THAT MUCH better than new 75Bs, and in some ways a bigger potential problem. (After-market sights, for example, are hard to find -- you may have to have the rear dovetail recut; the front sight is probably staked.) You can find a used 75B and have a good trigger job done, and have much the same gun without future "parts" issues.
My first pre-B was an even-worse deal, but the trigger was so sweet I couldn't resist it.
Only you can decide whether its worth it.