[A/S] Airstream power converter

[photovision@xxxxxxxx]

Greetings all.
I have been reading all the information posted on the "Univolt", 
Statpower, Inteli-Power, and others, but I have yet to see anything
on 
"Airstream Power Converter model PD-710" it is made by a company 
"Progressive Dynamics" 
http://www.progressivedyn.com/_frames/frames_rv_power_converters.html

We haven't used the trailer for a few years and the last that I 
remember the battery was fried, probably from overcharging. Im 
guessing that this converter has gone bad. BTW the trailer is a 
'71 31' Excella. This converter looks the same as one of two shown in 
my owners manual, so again I'm guessing that this is original.

The questions I have are:
How do you test the converter, measure the volts at the battery? OR

Should I just go ahead and replace a piece of thirty year old 
technology with a new converter, and would there be any advantage to 
replacing this converter with one by the same company, Progressive 
Dynamics, or it doesn't really matter.

One thing that I haven't seen addressed, is that my original
converter 
(I dont want to say Univolt, cause no where on my converter does it 
say Univolt and I'm think just maybe they are different) there are 
four 4 circut breakers for the 12v system. None of the other 
converters menioned have this. Sould I just add a breaker panel?

Thanks for you help and opinions.

Tom & Barb Beitz
DelVal Unit
#12069
Riverton, NJ