A friend of mine just showed me two pristine model 57's, both pinned and recessed. One is a 4", the other 6". He said he could part with one, so I'm contemplating buying one. I already own a 6" model 657-3. They both appear to be in like new condition - very beautiful. My question is - which is the more rarer of the two? It seems there are more 6" models out there. I don't know much about the model 57. Which one is generally more desirable, generally speaking? Just wanted a little input. Thanks. wyatte