It’s a Remington Model 11, which is basically an A-5. For a time, Remington held the US license while FN held the European license.
I bought it from a guy in a shotgun class for something like $160. It had been reblued and had three holes poorly drilled and tapped in the left side of the receiver.
Those holes turned out to match the hole pattern of a Williams peep sight that fits the Rem M11 and the M8 and 81 rifles. Well, two of the threaded holes matched. The third was drilled crooked.
I had the barrel shortened and a front sight silver soldered on. That front sight departed under recoil, so I went to the banded type it has now for more silver solder contact area.
The Rem 11 magazine tube cap has the same threads as the 870/1100/11-87 so it was easy to get a tube extension. Using angle steel, I made a spacer to go between the cap and the forend that mounts a light and has a slot for sling attachment.
The rear sling point is a footman loop from the hardware store.
It got all new springs. Aside from that, the only mechanical change I made was to replace the early-type carrier with a later style A-5 two-piece carrier so it will “speed load”. That has dropped the jaws of some who’ve never seen it before. The old style carrier required pushing the button to load each shell. What an improvement.
I think that’s about it. There’s a patch of Velcro on the LH side of the receiver for a sidesaddle but I can’t remember the last time it’s been on there.