[Slivver]

I recently bought at estate auction a J. P. Sauer & Sohn SxS double 12 Guage, serial #45906. I think I have sorted out most of the proofmarks (corrections welcome!) but I don't yet have a fix on the date of manufacture or value. I would appreciate any help. It does have external hammers, double triggers, 29-1/2 " Bbls, a round-body rebounding hammer lock system, a buffalo horn trigger guard, steel buttplate, and walnut cheekpiece stock.
Receiver and locks have gone to gray finish, barrels have pretty good blue ahead of the receiver. There is some surface pitting on the outside rear of the left barrel. Wood shows lots of dings and dents but is in overall good shape. Bores mostly bright but with some discoloration and light pits just ahead of chambers. There are 2 small dents on left barrel. Action is crisp with tight lockup. Unfortunately, sling swivels have been discarded. I think this gun began life as a black powder gun sometime before 1891 (Crown/V proofmark). It does have some more recent marks, including Eagle/J, Eagle/N, and 442. I think this means that it was repaired and reproofed in Suhl in April 1942. The ejector is suspiciously bright and smooth, and the lockup between barrels and receiver is also suspiciously tight. Take a look at the photos to see the proofs and condition. I have more photos if any of you have any specific questions. I have not found many examples of this particular gun on the Internet and I would like to know the approximate value (I paid $420 at the auction). Thanks for any help you can give!!