It's rare alright.

I got through about 2 minutes of that video.

The 25 is a economy model non-takedown Model 12 variant. It has a 6 shot magazine as delivered.

There would be no point whatever in having one engraved.

I had one. The action bar broke. I found a replacement at Numrich and got rid of the thing before the second action bar had a chance to break.

"The price of good shotgunnery is constant practice" - Fred Kimble