41s started in 1958. Since then, few engineering changes appear. Minor things like 5.5" to 5" or 7.375" to 7". Obviously older ones are more collectable but not just any old one. Unusual features like extendable front sight will demand more but only slightly more uless they have other features like box, papers, tool kits, and cosmetics. There is no noticable difference in shooting a 1960 compared to a 2000. You'll find some guys that lust after steel mag followers or 12 round magazines but all 41s have the same potential for greatness. Standard velocity ammo is S&W reccomended and in my experience works better in my guns. The most practical feature of recent guns is the fact that they come drilled and tapped for scope mounts but even that does not say that newer is better. Used prices will run from $650.00 to $900.00 according to whose company just went belly up. Other guys are more able than I to clue you in but meanwhile a search will reveal many pages of comments. Welcome to the world where guys talk of "lazy ampersands", "A" prefixes, bully bbls, and field models.