Dennis,
FYI Smith and Wesson did not record manufacture or "birth" dates. Their records were kept predicated upon the date that shipment was made from the factory. If it helps, K48054 shipped in 1948. Your granddad's gun is a K-22, 3rd Model (Masterpiece) (Pre-M17). IMHO, based upon the condition shown in your photos, the current value is between $775.00 - $875.00 depending upon the geographic region. Hope this helps.

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Doug