Good job documenting what is there, which is four Interstate SRM-24 deep cycle 12 volt Group 24 flooded lead acid 81 amp-hour batteries, wired "ganged together" in parallel, essentially operating as one battery.
Although your coach would have four times the capacity as that of a single SRM-24 battery IF all four were new and fully charged, being ganged together precludes having individual charging control or individual load control on each battery.
It has often been said that even for just two flooded lead acid (FLA) batteries ganged together in parallell, one will be working while the other will be sulfating and in decline. The solution for that problem, in an installation desiring to have the combined capacity of two deep cycle FLA batteries, was to wire two 6 volt golf cart batteries in series. That way, the two became "one battery" of series-stacked cells, with current flow and charging /discharging occurring uniformly thru the two battery lash-up.
Given that your SRM-24 batteries are rated 81 amp-hours capacity each in the Interstate spec sheet, the four of them had a combined maximum capacity of 324 amp hours. In practice, you could now have three that have declined and sulfated, existing as "zombies" in the ganged set and resulting in only the newest one contributing any capacity.
You could remove all four of the old school flooded lead acid SRM-24 batteries and instead use a single 300 amp hour LiFePo4 battey with an upgraded replacement power converter (a lithium battery capable one) and accomplish what the four gang set was intended to provide, with greatly reduced weight, no acid drippage exposure nor hydrogen gas emissions, and the battery's internal BMS (battery management system) would keep the groups of cells within it balanced up just right, all on it's own (with a proper Lithium-service converter upgrade in place).
As for the wiring of loads attached to your system:: The parallelling of the four batteries created a single battery equivalent circuit. Yes, you have a breaker connected to the gang's circuit for one load branch and a fuse connected for another load branch. In a single LiFePo4 battery system, both loads are to be connected to the single battery, which electrical circuit wise, will be just the same function as the ganged arrangement.
I upgraded our 2019 Intech Flyer Explore TH from a single group 24 FLA battery to a 300 amp hour LiFePo4 bought via Amazon, plus a simple 20 amp power supply designed for Lithium service. (We don't boondock in the TH, so 20 amps recharges fast enough). Recently bought Mrs T a 2026 Intech OVR Navigate, which has a single 368 amp hour Expion model 360 LiFePo4 battery, rooftop solar and an inverter. Magical battery based performance there!
Looking back, our two golf cart FLA batteries that I put wired in series in the 1989 P30 Holiday Rambler motorhome that we had when the kids were young gave about a 210 amp hour capacity. Replaced those batts every 5 yesrs. Sometimes found the electrolyte boiled off below the tops of the cell plates from being on the unsophisticated standby converter charging circuit. I don't miss having to deal with all of that, from those bygone days of olde!
Perhaps you can load test your SRM-24 batteries individually after you pull them out. Might be three "zombies" there! If you can charge up each one individually on the bench before load testing, that would be best..
I pray that you will enjoy happy and safe camping, always!
