Hi
When you go to drop in the Boondocker, you have a couple of choices. It's designed as a deck mount and what you have is in a drawer sort of thing.
1) You can tear apart the drawer and use the remains as a deep tray to mount the new one. Four bolts / holes are involved in doing this. The wires just barely fit.
2) You can build a shelf for it that goes in pretty much where the old one sat. This likely involves some screws into the floor in some awkward places to get to.
3) You can deck mount it a bit far away from the original location ( just where varies by model) and extend some of the wires to get to it.
None of those are a "best choice". I went with number 1. Like you, I tossed the one year old dead converter in the trash. Some of the burn on the board is from resistors ( = it's normal). Mine died when the LM317 broke off the board and not from any burning process.
One note:
Be careful of the line that runs to the battery. Either tape it off or pull the negative on the battery. Do as I say ... not as I do
Sparks can fly if the cable hits something ....
Bob
Bob