Help me ID a shotgun

[tdo315]

My father-in-law was visiting his 91 year old mother out in texas last week and she sent some old guns home with him. We are in the process of getting the paperwork sorted out and I was wondering if anyone recognizes this old shooter. There are no markings other than "012509" on the receiver under the barrel. My FIL seems to think that it is an old Stevens .410. Any help is appreciated.

[TRAP55]

Looks like a Spanish Import, it's not a Stevens.
Can you break it down and check the bottom of the barrels, and the water table (flat on the receiver under the chambers} for proof stamps?

[Utha Schleigle]

Are you sure it is a 410 gauge. Also look for 60 65 70mm any where on the barrell for chamber length, It looks pretty modern. I am probably wrong but it looks like a 20 gauge. If it is a 16 gauge you must have the chamber length measured.

Rust removal procedures are called for before shooting. You can see the rust on the photos.