Lower the stem, raise the seat post, three nice photos against a white wall with similar angles as the ones I have here and you should get $250. For a race bike, you want to make it look fast, forget about fit.

As others have said, Centurion is a brand that we all know here on BF as excellent but you will have to get that across to the buyer so maybe selling the components is a good idea too. "The Shimano 600 components are second only to Shimano's legendary Dura Ace line and were typically used on bikes intended for amateur racers" or something like that, I can't write anything worthwhile until at least my second coffee