I've done extensive electrical
work on our Burro so I have come to some conclusions.
If I were in your shoes I would mentally and otherwise prepare to part with most of the Newmark. The 120v part (breakers) are OK, but the 12v charger and distribution panel is a disaster and in our case was a serious fire danger. It will boil out and destroy your battery, etc. and puts out very poorly regulated 12v juice (ours was a model PCS 20RAC). There seemed to be no way to locate the manufacturer either.
If it is the same model as ours you can replace the converter section with a Progressive Dynamics 9245 converter for four-stage charging without the noise, weight
, and general dumbness of the Newmark. I would guess there are other makes which would also do well.
Another recommendation is to replace the 12v fuse panel with one by Blue Sea Systems (West Marine). The original tubular fuses and their holders are extremely poor and resisted all attempts to improve them. Repeatedly tried to start fires as the poor contacts melted and charred the panel.
I'd be happy to give you all the information and pictures I have, since I consider this to be perhaps the most iffy device I found on the Burro we have.