If they're complete rifles/carbines, and in very good or better condition, they're worth $$$$ to collectors as they've been out of production for quit awhile. If they're less than "very good" ,,,,,, well, aftermarket is very limited. Not sure if triggers made for the 700 will work , or not. I know the bolt release is different but there is an add-on for that. I'd have to measure the one in the shop to find out if SA 700 bottom metal will work, but I seriously doubt it. The originals have a blind magazine and cheap plastic trigger guard. Not my first choice for a 'custom build'. Evidently, triggers for the 700 won't work as Timney offers a seperate trigger for the 600. Scope mounts can be another issue, as only a few are available "off the shelf".