I'm curious as your sig hasn't been updated -what camper did you end up getting?
Well they do make male/male already made up. I'm unclear why if its working you want to make another male/male plug and /or why you don't trust it?
I am also curious why the dealer used 2 different style male ends. Don't know but possibly cord & one end was supplied by camper mfg-other end to be matched to whatever style plug on truck by customer/dealer. Could also be the 90 minutes was having to trace out wiring if camper non standard, which if thats the case an off the shelf pre-made cord might not work (or need re-wiring). were you instructed that one specific end of cord went to camper?