Rock Defense bumpers on a first gen.?

[dusty husky]

I want to get a winch bumper and matching tube rear bumper for my 1980 mini and marlin and Dave's seem to always be out of stock. Can i use the X-member adapter from daves and bolt up a trail gear bumper? As far as I can tell the 1st gens are just missing the upper two bolt holes on the front x-member. And how far off is the rear bumper from mounting up. FYI , I searched the faqs on here and pirate but didn't find anything. It would be nice to have more options than two out of stock websites. Thanks