What kind of trailer hitching mechanism?

[friz]

New to me 2016 F-250 6.7L. Need an assist in identifying the hitch that went in the bed. Dealer could only say "gooseneck" . The 1st photo is of the bed. The larger center circular hole has nothing in it. It does look like a ball went there. The first set of four holes around the larger circular hole are drilled through the mounting frame under the bed.

In my 2004 F-250 I have an EZ Lift retractable ball. Doesn't look anything like this one. Not even sure if it was a gooseneck at this point.

The second photo is the mounting frame for whatever was attached above. There is not any mechanism for a retractable ball. Everything looks static.

The 3rd photo is of a pad which sits between the mounting frame and the underneath of the bed. The numbers on it are interesting. One starts with FOMOCO. Have not googled the numbers as of yet - next.

The fourth photo is of a number cast onto the mounting frame. May just be a casting number.

Any help appreciated. Obviously I am stoked about my new toy.

Thanks, Friz