Sounds like you need to equalize the heck out of those batteries and start over. Meanwhile
The PM 75 amper will take the batteries up to 14.6v then the converter drops to 13.6v and stays there while amps taper. With 75 amps on a 430AH bank, that is a 17% charging rate, so expect your SOC when reaching 14.6 to be about 78% Now you have to get from 78-100 with a Vabs of 13.6. This will take a very long time (two days? I don't know when it drops to 13.2, but not for a while.
Even then you will not be getting the batts to 100% since that takes a Vabs of more like 15v, which converters don't do. So you really need two chargers. One that can get the batts to 15+ volts and also your converter to supply 12v (13.6) on shore power. I use a VEC1093DBD for charging to 100% and then doing an overcharge/equalize before leaving the batts on the converter for their Float.
BTW having the batts under the bed is ok if they are in properly sealed battery boxes vented to the outside. A lot of those boxes have their lids not down tight because the battery cables are not placed properly.
