RGN trailer rollers (to roll the neck onto the truck)?

I bought a mechanical RGN trailer. I am trying to add a ramp to the truck and start using it.

It has rollers that roll up the truck frame when I pick up the trailer. The problem is that these rollers are in poor condition and do not rotate easily.

I would like to torch cut them out and replace with new rollers.

The problem is, when I search for those things online, I am not finding much. I suspect that I search for the wrong term or name. How would I find them for sale?

 

but what are those rollers called in proper trade terms?

 

One of them has a grease fitting that is broken. Another already has no grease fitting whatsoever and clearly was somehow rewelded or otherwise repaired, which removed the grease fitting.

Looking around, I recalled that rolloff containers have rollers, looked for rolloff rollers, and found some "nose rollers" such as "4x6 nose rollers". Clearly heavy duty rollers.

Making brackets for those, torching old rollfers off, and welding new rollers on, is not a problem for me.

So, if you guys think that 4x6 rollers are acceptable, I will simply buy those and be done with it.

 

I will definitely call Trailking tomorrow, that's a great idea for sure.