Germany did not adopt a proof law until 1891. So I think this gun was most likely made for a retailer, by some German or Germanic gun makers which would explain the total lack of proof markings. Kind of like Lindner for Charles Daly consortium. Recall Lindner changed his marking after proof started because they were too similar to the proof mark that the proof house used. If it was a special order or one of just a few it might explain why we have not seen an example before. There are all kinds of odd guns out there which get very little attention because most ever pop up on our radar screens. I assume the lever on the side is a sidecocker for the hammers, which time line wise is about when LeFever went away from a similar setup. The window to check the status of the hammers is interesting but no alone for that time period. Good features were copied all the time if patent laws did not protect them.
