I don't know how "handy" you are, or what tools you have available, but I did one myself, and I'm about to do another. (NOTE: these were NOT collectible guns, one was a Turk, the other VZ-24, both with markings ground off, junk stocks and shot out barrels. But the actions were good).
You need:
Small center drill
A nice sharp high-speed steel (or titanium nitride) drill bit...I've forgotten the size, but you can find out the proper size for a 6-42 tap/screw.
A 6-42 tap (NO cheapies--get a good one)
CUTTING OIL---WD-40 will work in a pinch
A drill press.
Make sure you get the action dead-level, and clamped in the drill press. CAREFULLY mark the holes, based on the scope mount you're using, making sure its dead level (as best you can). clamp it on if possible. Prick punch the holes, or use the center drill to start the holes in the center, of the mounting holes. Most of the Mounts use tapered screws so you have a little leeway (but not much!)
Once you have the holes marked, progress to using the drill bit...Drill reasonable slowly (not much pressure) spraying lubricant liberally. Once the holes are drilled, chuck the tap into the drill press, and start tapping, turning the chuck by hand. THIS WILL ENSURE THAT YOU GET THE THREADS STARTED STRAIGHT). After all the holes are started with the tap, you can remove it from the vise and continue tapping with a tap handle. Use pelent y of oil, and back out the tap ever 1 to 1 1/2 revolutions (YOU REALLY don't wanna break a tap off in there. Tape until you've acheived the required depth for the mounting scres.
Sounds complicated, but you can do it in less time that it took me to explain it.
