My Elixir 45 charger recently died and I did the 1245 replacement.
Before even starting I realized I was in for a nightmare of a project. The replacement required replacing all the incoming and outgoing connections with new buss bars, fuses and breakers. All of this had to be done in a very cramped space with wiring that was cut to fit without any excess. Next my Elixir also had a built in transfer switch. It was not clear how I would be able to remove, rewire and reuse the switch. Next I was going to replace the heavy duty metal box, fuses, busses and breakers etc with a thin plastic box which arrived with a cheap door latch that was already broken.
You can probably guess that instead of this massive project, I switched out the charger/converter. That was better than the alternative, but still not easy. I had to cut ventilation holes in the old heavy duty metal box. It is unfortunate that the boondocker charger/converter is slightly larger than the original Elixir parts.
It sounds like this solution would work for you as well.
