Went to an LGS yesterday and found this. The Lyman 57SME sight caught my attention, I've wanted that sight on a Springfield rifle for years, so picked it up for $440. It is extremely clean. I ran a patch through it and it came out very light gray. That never happens to me on a used gun. It is not worn in the bolt recess area where you would expect it, very smooth action and all it has on it is safe dings and the checkering is very well done and not worn at all, except for a bruise on the left grip area. Serial is 116430. The searching I've done says made between 1953-67. If anyone can give more specifics than I have found, which is quite thin, then I'd appreciate it.