I did some more investigating on how the MkIII Troopers were built. The trigger, hammer and other parts were made from sintered metal, then case hardened. This means that you cannot hand fit any parts, once worn out, you would simply replace them. This design was intended to prevent the wear and subsequent maintenance experienced by owners of the Colt Python.
The owner of this gun had already replaced the trigger on this gun with a new or NOS one.The original one had a crack in the pivot hole.
The first step in any restoration (after the evaluation) is dis-assembly.
Colt revolvers are famous for being overly complicated. This one wasn't too bad. Also if you know your Colt revolvers you may not recognize these parts, they are quite a bit different from the classic colts like the Python, Police Positive and Detective Special.
for comparison, here are the internals of a 1973 vintage Colt Detective Special
The cylinder was 1st on the list of parts to work over, since it has the worst of the pitting.
I discovered the pitting is just too deep. While attempting to remove the pits, I removed too much metal (in my opinion) from the cylinder stop notch. There is another notch that is so badly pitted that I think it will affect the lock-up and may render the gun unsafe to shoot. I think we should look for another cylinder.
This brings up the question: How much money should the owner put into this gun? After searching Gunbroker, I can safely say that spending $200-$300 on parts would be a safe investment, these guns sell for $600+ in good condition and $800-$1200 in very good condition.
Making some headway, I was able to get most of the pits out of the trigger guard...baby steps
I almost have the front of the frame/crane done, when sanding these two parts, you need to have them assembled to ensure both parts remain flush to each other
Progress on both sides of the frame. Here you can see the side plate is getting smooth, again although the Colt rampart logo had to be sacrificed. Maybe we can have a laser engraver re-engrave it?
This is painstaking as I have to be careful of the rivet pins in the side of the frame.
Good News.....I was able to secure this vent rib barrel from a Mk V Trooper on ebay for just $45 including shipping....The bore is perfect and the finish is about 90%, no pits or scratches.
Now I just have to find a cylinder
Another score! I found a local guy who had a stash of factory replacement NOS parts for a Trooper Mk III, including all the internal parts & springs, a mint (new) hammer and trigger, mint condition cylinder latch, a new side plate with new screws!
I started on the ejector rod & rear sight, believe it or not they were pitted too!
I measured out the part that would stick out of the cylinder, taped up the part that wouldn't and chucked it into my drill, so I could sand it with 100 grit emory cloth in an expedient fashion
After I had 90% of the pits removed, I stepped up to higher grit paper and then the buffer
The rear sight is made of a cast or sintered metal, not very hard.
I was able to file out most of the pits, then sanded with 220 grit paper. The front part was sand blasted to give it a non-glare sight plane and to hide the small remaining pits
Unless I find a new or better looking sight, this will have to do.
I mounted the side plate, I noticed that I will need to do some filing and sanding to get a flush fit.
EUREKA! we were lucky enough to find a reasonably priced cylinder on ebay. I now have all the parts to begin the restoration in earnest. Stay tuned for part 3