I have recently purchased a model 51. It has the standard .22 mag cylinder, plus an additional .22 LR cylinder. Looks to be 98% with original box and paperwork. Trying to establish date of manufacture and approx. value.

A serial number would be a real help. So would a decent pic!

VERY nice snag by the way. And Welcome to the best S&W site on the internet.

FN in MT

Welcome to the forum.
We need a little more info to help. If you post the serial number we can give you an approximate ship date. S&W only kept records of when a gun shipped out of the factory. If you do not want to post the whole number just x out the last couple of digits.
Pictures would really help with value. Or at least a very good description of the condition.
That's a model I do not see for sale often and the extra cylinder is certainly a bonus. Maybe some of the other guys can help with the value.

I saw a 651 on GB awhile ago, I think it went for $1,050.00 if I remember right.... I wanted it so bad, but I stopped bidding at $800.00. I would love to see some pics as well.

From the information provided so far, we can tell you with fair certainty that your Model 51 was shipped between 1960 and 1974.

Any closer than that, we need more help.