So I’ve come across a strange beast called a Fortona Special gewehrlaufstahl. It’s a triple barrel shotgun with sxs 20 gauge and I think a 7mm below. There’s also a insert you can but in one of the 20ga barrels to change the caliber. Thats all the info I have right now. Going to look at it this weekend. I’d say it’s a 40-50’s make and very nice with a bit of scroll work but nothing over the top. Well worn but still got n good condition. Anyone know anything about these things?