i just came into possession of a 1965 schwinn paramount road frame. tubing is reynolds 531. there's a pretty significant ding in the seat tube and i'm wondering about fixing it. an auto detailer friend of mine recommended hammering a brass tube of the same diameter (27.2mm) gently down into the tube. this sounds sort of sketchy so i'm looking for advice on this technique or any others. thanks for helping me straighten this out (ha. get it?).