Pretty cool! Looks like you have nylocks all over it. Don't let that nice vise rust out in the weather
I would be worried about the swivel-lock vibrating loose and being gone foreva. Maybe a little steel cable or lockwire lanyard around it or something else? Sometimes removing that can also release the vise....maybe it deserves some blue loctite. Just a few ideas. Thats got to be very useful out in the field.
Posted in wrong sub forum, meant to post in general tool discussion... Sorry guys.

Nice set up, do you use this set up for a crane too?
Taken care of, not a big deal nor need to feel sorry.
Ag equipment service ?
Fluid Film is your friend on bumper vise mounts, at least here in the PNW.
Look at Princess Auto truck cranes, they have a few diifferent models you can get ideas from. Here is a link to a modified Princess Auto receiver mount crane
https://www.princessauto.com/en/project-showcase/2015/05/portable-crane
Regarding vises, i seen and commented on a thread about service truck vises. Can't remember the title though.
Some guys like them solid and low on the passenger side, others like your self have them higher and detachable on the drivers side. Couple of pictures of trucks from a Ritchie Bros, auction that I went to
I built a vise that slides into my receiver hitch. It's long enough that is just sticks past my tailgate when it's down. It gives me a portable work bench. It's not a heavy vise but it's good in a pinch.