Mis-matches are usually worth the sum of their parts. Take an BCD 4 LSR for example, which is the easiest in my opinion. You can usually find all the parts if you search for a few years. They pop up. A barreled receiver will cost $1000 to $2000. A bolt with LSR key safety will cost $300 to $800. An original LSR scope rail and screws $700 to $1000. Original Sniper checkered butt plate $800 to $1000. A stock you will have to cut for scope rail will cost depending on originality and condition. Original LSR stocks are rare and very expensive if you can find one that is not sanded. Original stocks usually go to matching examples that have stocks that someone cuts and tries to call it original or sporter stock replacements. The rest of the parts maybe $200. Also a scope and mount is needed. Just depends on type and condition, but cost is anywhere from $1500 to $2300 for a BEK scope and 5 digit mount. If optics are bad then $300 to clean and put a new reticle in scope plus postage and insurance to a guy who fixes it. Or maybe you will just luck into one for sale that nobody knows about.