Coincidentally I looked at one of these three round guns today in 12 ga with the front guard safety. It is an ancient Cutts-like compensator whose name I forgot but it had broad chevrons cut into the barrel/body. This barrel also had a solid tube from the muzzle going back to about 3/4" from the muzzle.
I got the impression this was a thirties item as I was casually familiar with one of that era I almost bought. This thing had a 26" bbl and I think that included the muzzle device. This could only be a skeet gun or something for dedicated close range shooting. Price was $349 possibly as a consignment. Condition seemed pretty good overall and were it not for the barrel I might have bought it. I still might and toss it in with my Browning pile. On the other hand there was another light 12 of Belgian origin with a speckled receiver (too long in the attic) which was nonetheless restorable as regards finish. Asking price too high at $599 as I bought much better guns of the same type from the same place at the same price.