I took a few pics the last time i started dissasembling a 600 and figured someone would like to see why they say to send them to someone who knows them. There are other tricky issues with 600,s besides the trigger but man are they a fun gun.
The barrels in 600,s are a small diameter barrel so if you want a long barrel just pick up a 2260 (24 inch) barrel and turn it down to the correct o.d. I had that one turned for me by a friend. I still haven,t got me a lathe yet but very soon.
RJ Machine is in the process of making up some barrels for the CR600 using stock Crosman barrels. I believe they'll be 12" and the price should be reasonable.