OK,
It's continental European, as shown by the choke markings in milimeters.
SPI I'm not familiar with, unfortunately.
It's got the general look of a generic Belgian gun.
The strange symbol is probably the proof mark, and would tell you where it was made, and possibly generally when, but I think manufacture date is probably sometime between 1880 and 1900.
Oh! I can make out a proof mark on the underside of the barrels near the locking block. ELG in a circle under a crown is, IIRC, the mark of Liege, the big proof house in Belgium.
I can also make out "Full Choke" on one of the barrels (monitor at home is a LOT better than the one at work), which to me indicates it was made pretty much for the American trade, or else it would be in French.
I think you've got a pretty common "shop gun" of the period. Tons of inexpensive guns made in Belgium around Liege for export.
