Now that IS odd! Looks to me to be a "mixmaster" of various Savage and aftermarket parts:
Buttstock looks like a Savage Model 24
Action looks like a late Utica with alloy guard and trigger, or an early Chicopee Falls (but why no model number? Reblue scrubbed it off?)
Forend aftermarket or heavily redone factory
Buttplate home made
Front sight aftermarket
Rear sight aftermarket redone to "fit" Savage barrel
The barrel is very likely one of the leftover R&D barrels from the closed Utica plant that were sold by Numrich Arms in West Hurley NY in the 1980s, but this one has been rifled after sale, or was rifled after finishing as a 9mm RF smoothbore by the Savage R&D shop.
I remember seeing 9mm RF barrels among those for sale by Numrichs, but don't remember what length they were. I do remember seeing a .357 Rem Maximum barrel among that lot also, but no .357 Magnums, and the .357 Max was not a "double-stamped" 9mm RF. (Actually both .357s would make sense in a 219 for deer woods duty since the .357 in a rifle is much more capable than in a handgun. Savage chambered the Model 24 for those calibers for a short while).
While I'm very glad that the original poster drew our attention to this piece, I would consider it just parts at this point. 9mm Rimfire shot ctgs. are still made by Fiocchi and perhaps other European cartridge makers, and guns for them are still available in Europe.
They are used for killing pests in the garden (called "Garden Guns"), and for specialized hunting of edible songbirds in some countries, especially their large thrushes which are a delicacy in Italy ("Tordos"). This hunting is increasingly condemned by bird lovers in Europe, and, of course, has long been banned here and in England.
