off/limited production? or hand made
I always thought custom meant that the item has to be made to the individual customer's exact specs.
But there are a lot of things that say custom that are just hand built or not massed produced like gibson custom guitars.
I find it's usually It's easier to pull a certain amount of Weight in a wagon than it is to carry it, but I don't have wheels...
Don't say anything about the trailer's weight having to be accounted for, if the weight was the same.