Thank you for each reply. To say I'm disappointed that the dent at the bottom tube appears to be serious is an understatement. I feared that might be the case - that it might be from a crash. I did see the dent, but not being all that knowledgeable, well, you live and learn. The fork, I'm certain, is okay. Comparing it to the other Centurion, in which the frame is unblemished, indicates they are both okay. The seat post moves easily - I adjusted it to my height and rode it about 3 times for a total of about 2 miles.

Not sure what I might do at this point. I still will clean it up, but not spend any money on it for any parts. I only have 50 bucks and gas money in all 3 at this point. Unfortunately the other 2 frames are not in my size, so they will not be any use to me.

It was difficult to find even this bike in my area - sellers on CL here may or may not respond quickly to a listing, and even if I respond quickly they take their time getting back to you, don't list things like the size, provide minimal pictures, and so on. Frustrated at this point.

Thanks all.