I want to buy a frame so I can start building up a nice bike to ride around. Came across this on craigslist, she says it's a px10 from the 70's. it has the reynolds tubing sticker and the serial number on the bottom bracket reads 1814685. Can anyone identify what the serial number means in terms of the model? Also the lugs are black. http://sacramento.craigslist.org/bik/1049602215.html