Picked up a DS at a show on Saturday. 2" with covered ejector and original wood grips. Looks to be in excellent shape with very little wear except rifling looks worn to me but then I'm no expert. Maybe it's a used piece that has been reblued. My questions are: Does anyone have an idea of its vintage based on the serial number (B504XX)? There was no book. Where can I find instuctions on break-down for cleaning? The seller thought it was early to mid 70s', would that be a third issue? Is there anything else I should know about this gun? Thanks in advance for any and all replies. Al