I think I know which Superposed you're speaking of. In La Belle Province, oui? If so, it is indeed a prewar superposed, however the lever is quite far to the left past the safety, indicating the likely need to be serviced by a competent gunsmith in the near future, if it is to be put into service.
It's a nice gun, but I don't really think it's a screaming deal. It has a fair amount of pitting on the receiver as well in the additional photos they sent me.
Post pics here if you do end up buying it, it would be cool to figure out whats up with it.
