Let's look at the ENTIRE situation:
Post #19: "gotta look out for my son and myself, as this is now our home"
Does this mean this is now a full-time residence? If yes, it seems like other electrical appliances, some of them heating type, would be desired. Coffee pot? Microwave and/or convection oven? Computer/phone charger? It would seem like additional 120v AC household outlets would be desired, other than the one the converter is plugged into.
Post #25, "I will be also upgrading my old propane furnace to that of an electric one, so I know I will be upgrading the electrical"
This sounds like some type of electrical space heating is desired.
Post #25, "the ac has a slow blow round fuse"
I would want to replace the AC fuse (which I assume is the old fashioned screw-in type) with a circuit breaker, preferrably GFCI.
Post #29, "I added a hot rod to the cast iron water heater"
Electrical heating has already been added to the water heater.
Because of all of the above reasons, I stand firmly behind my recommendation that the 120v AC side needs to be upgraded to a circuit breaker panel 30 amp main service and 15/20 amp branch circuit breakers.
A standard RV complete power center would take care of everything in one single box.
And what is that which is highlighted in the photo below? That looks to me like either the AC neutral or the DC ground "buss". That definitely needs to be replaced with a buss bar, and if it is AC neutral, the RV power panel will have the AC neutral and AC ground buss bars built into it.