Stripped "Yellowstone Park" off bus.

We will paint the roof Blue in memory of Maui, Hawaii and it was already one of my choices since l want to use old school enamels like it was done in 1975, solid colors no metallics. The sides will remain Silver, might tint windows to match too? The batteries are old (2012) serviced last in 2014 lol, so l put a slow charge on them for a few days, than let them set a few days then did a normal 15amp charge three different times so they seem to hold at over 12.6v but l have another new battery to add if needed later on. Which brings me to another idea, 24v Inverter system with our solar ? So in case it was ever an issue l would always have power to start the bus? I have 2 different Inverters, a 12v and a 48v, and planned on using the 48v Inverter so l am thinking, which one is best, lol?