"LIG" or La Industria Guipuzcoana, was a consortium of gunmakers in Elgoibar, a town in
the province of Guipuzcoa (somestimes spelled Gipuzkoa) in the Autonomous Basque
country of northern Spain, northwest of Pamplona. Most of the the Spanish gun trade is centred in two of the towns of that region, Eibar & Elgoibar, maybe 5km apart from each other and 15 or 20km south of the Bay of Biscay. Both are not terribly far from the border of south-west France to the immediate east.
From the markings, it's easy to see '12 / 70' denoting 12 gauge, 2-3/4" chambers, and what appears to be 850 the Spanish proof house test. Looks like lead shot or soft non-toxic only. Not clear, but the chokes appear to be 17.3/18.5 and 18.1/18.5 ... if so, convert from millimetres to inches, 0.681"/0.729" or .048" constriction ... a very tight 'Extra-Full' and 0.713"/0.729" or 0.016" about 'Light Modified' (Between I.Cyl & Mod) Elswhere I also see 18.3 farther along on the barrels which when converted would be 0.720" ... somewhat tight for even European bores, so I'm not sure what that may refer to.
These guns were reasonably well-made and solid doubles, perhaps described as lower-end doubles, but certainly not Spanish best
I would be very tempted to pattern the gun with standard 7-1/2 trap loads at 16 yards to see how it fits... and at 40 yards to see what the chokes actually deliver as opposed to what they are marked.
As to value, maybe $400 - $500 if an extractor only, and maybe even a couple hundred more if it's an ejector. Quite difficult to find anything of comparable quality in that price range... and if it fits... by all means, use & enjoy it !