Finish would be of far secondary concern to me opposed to operation.
A series of basic checks for -Six revolvers: (All thanks to Rugerforum.net long-time participant, moderator and gunsmith Iowegan, and found in "Iowegan's Book of Knowledge for the Ruger Security-Six, Speed-Six, Service -Six, and Police Service-Six" pp. 2-4:
To check for Endshake: With an automotive (or gunsmithing) set of feeler gauges, hold the cylinder to the rear, and slide the thickest gap gauge blade that will fit between the rear barrel surface and the front face of the cylinder with considerable friction. This will be the Barrel/Cylinder (B/C) gap, and should be between .004" and .008" with .006" being optimum.
Repeat the same test only this time hold the cylinder forward and insert the thickest blade that fits with minimal friction. Subtract this measurement from the first (B/C) one; the result will be your cylinder endshake, which should be between .001" to .004."
To check for Headspace, chamber a virgin empty case in a chamber and line up with the firing pin hole. While holding the cylinder firmly to the rear, slide the thickest gap gauge blade that will fit between the case head (rear of the cartridge) and the recoil shield (frame). It should measure between .008" and .012," with .010" optimum..
To check for Timing, swing the cylinder open and look for the cylinder latch that is located on the bottom flat area of the frame, just above the trigger. Now close the cylinder and rotate it slightly until the culinder locks up. Watch the cylinder latch from the right side as you begin cocking the hammer. The cylinder latch should drop and free the cylinder before the cylinder actually begins to rotate. Do the same test in double-action by pulling the trigger and watching the cylinder latch. Again, the latch should drop before the cylinder begins to rotate. If timing is slow, the cylinder will try to rotate before it is released, which will cause a bind in DA trigger pull or a hard cocking start for SA. A worn or out-of-spec trigger or cylinder latch will cause late initial timing.
Carry-Up timing: Carry-up is a condition where the cylinder is supposed to lock up near the end of a hammer stroke. To test, watch the cylinder latch and slowly cock the hammer. The latch should drop, then pop back up and drag on the cylinder. The cylinder latch should engage a cylinder lock notch and lock the cylinder in place BEFORE the hammer is fully cocked in all six positions. Again, in DA mode, slowly pull the trigger and make sure the cylinder locks up in each of the six positions before the hammer releases. An excessively premature carry-up can cause a trigger pull gag near the end of the trigger stroke. Late carry-up could allow the gun to fire before the cylinder is locked. Normally, -Sixes tend to carry up a bit early. A pawl that is too long causes premature carry-up. Late lock-up is caused by a worn or out-of-spec pawl or extractor ratchets.
Trigger pull: Normal SA is 6 lbs, DA is 14 lbs.
Push-Off: The sear is designed to hold the hammer cocked in the SA mode. If the sear is altered or defective, the sear could release by pushing on the hammer. To test, cock the hammer and apply considerable forward pressure to the top of the hammer. Do not over do it, or you will break the sear. If the hammer pushes off, you'll need to repair the sear or replace the hammer.
Cylinder Lock-Up: To test, dry fire the gun and hold the trigger all the way back to simulate the condition of the gun when fired. Rock the cylinder from side-to-side. A few thousandths play is normal. If side play is excessive, a new cylinder latch may be needed.
Best, Jon