I'm wondering if anyone has information about an O/U shotgun? One side of the barrel says (Incor Inc. Addison Texas USA) and the other side says (Model SL-55 20ga 3" Magnum made in Italy). I can't find any information on the gun. It is a beautiful piece just like to know more about it.

Thanks for any help in advance.

Probably an import name for a Rizzini. My US import "Verona" was made by FAIR aka Isadore Rizzini. There are three Rizzini brothers, three different companies. There are other importer names used on US imported Rizzinis over the years, but I don't know what they are. Maybe see if you can find any maker or proof marks on it and see if there are any images of Rizzina markings online to compare with to see which one it is.

I have looked that thing over a couple of times. I'll have to get it out in the sunlight and check again. Thank you for the information.

I found this post about the Rizini shotguns. On page 2 someone asked about the same model as the OP back in 2019.

https://www.shotgunworld.com/threads/there-are-four-different-rizzinis.69662/#replies