SATCOM,
Glad you enjoyed the pick and could spark little curiosity. Hope you can find a tri-color second. Definitely one of my favorites. Looking for a blued second now.
Not sure what you are referring to as the defect? The off color portion on the cylinder frame near the cylinder rod button is grease applied little think. Unfortunately i'm aware from them for long periods and have little bit better piece of mind doing that, the spot on the cylinder is a reflection.
This pistol was my second or third Ruger revolver and the one that sparked my start and interest in collecting. I purchased it not because of rarity or collectability but its balance and fit in my hand. After researching it later I realized what it was.
So the odd one... Any guns I customize are so far out there or parts guns I try to fix. I've had people tell me that this and the second's cylinders where switched. They don't fit, tried it once. I bet there is a fun April Fools joke in there some where with the right person and set up though.
I know little about the pistol, some you just have to buy when you see it. I do know i'm the second owner. The first owner has since left us. He was a great guy I only knew through the local sportsman clubs. Never knew his interests in Rugers until his wife started selling his guns. (posthumously) From what I heard he had a good friend or relative that worked at Ruger and would get him some of his guns. He had early guns of different models and some oddities or short run variations. My best guess is this falls into the "parts bin" theory i've heard mentioned before. The serial number sorta fits; 205831
Hope this answers some of your questions.