You may need to find a true gunsmith that can make one. Your pistol was imported 1962-68 by Tradewinds, Inc. Imported for so short a time, and that long ago, finding parts will be a matter of pure luck. Sorry-
50-250 usd
Go here for some information - http://www.littlegun.be/arme%20belge/artisans%20identifies%20q%20r/a%20robar%20gb.htm
S&W can tell you when it left the factory if you call them.
gunparts.com
32
32
A place which carries parts for that pistol, presumably. We'd be happy to direct you to such a place, but we can't, since we have no idea what the make and model of your pistol is.
The factors of 622 are 1, 2, 311, 622
Divide by 622.
Frame barrel hammer
Depends on which parts, for which pistol. A good start would be your local gun shop. You may be able to order parts from the manufacturer, or gunpartscorp.com. Some parts can be installed by the maker, but are not sold to others because of the need for fitting.