Looks like it is in really good shape. Standard Catalog of S&W says that an excellent example should bring aroun $500.00 so I think you did OK. What it all really comes down to is, If you are happy with it, then you paid just the right amount.
As far as putting a manufacture date on it, I could not find that Prefix in the Catalog but these Alpha prefixes are spotty to say the least. Someone might be able to nail it down for you.
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