Another thing one has to take into consideration with custom or hand built guns, is the use or fashion of the day. Pachmyar and Swenson built 'combat' style pistols in the early days. Those guns can still be used as a shooter, range, or carry gun. Shockey was known for and built mostly match pistols; a sport popular in the era but unfortunately seems to have withered since then. The match pistols and revolvers are pretty much single purpose. I have to add that match pistolsmiths even today, seem to focus on function over looks- thus there are a LOT of good shooting handguns and rifles out there that most consider butt ugly. Name counts, too. A plain, good condition, late 60s GM nowadays sells for say, $800-$1500. That same gun tricked out by Swenson with his signature touches and marked by him would go for $3500-$5000. A gun built the same way, that anyone would consider quality work or even a bit better but unmarked or marked by an unknown, would probably go for more towards the stock gun's price.
I collect custom 1911s and revolvers. I shoot and carry them as well. My recommendation is always pay a little extra in money (and usually time!) to have a 'name' smith modify your gun as there is a MUCH greater chance that you will get the return on your investment if you need to sell it as opposed to another "bubba'd" gun on the market.
A10ACN