Patrol tension question 24? 12?

hello, I have asked a few questions again I bought an old 160er patrol with 24 volts on board voltage and gave the carousel to the scraper dealer (there was nothing more to do) and pulled me one of the 260er which now however with 12 volts have operated everything. now come the problems should you rather keep the 12 volts and install yourself a wrap-around relay and remodel the glowing candles? or rather implant the wire harness together with all the devices from the 160er into the carcasses of the 260er?? has j demand n schematic for such a switching relay where the starter then gets his 24 volts? can I charge the two batteries that are now always necessary with my 24 volt light engine (generator)? or do I need one with 12 volts? to which terminal of the light engine you have to attach a speedometer ? has someone n schematic for? for advice has an open ear mfg stephan