thanks everyone, for your thoughts, there is a strong attraction to a "real Lister" as a kid we had 32volt lighting, and then a start o matic, to keep mother happy.
i used to turn the light on to hear the engine start, when i was small.
it run till the mid 70,s when they got power.
We had a 3 day blackout this year and we survived on the 24 solar panels on the roof, and an old Honda e2500.
So there is an excuse to put something together just in case. So i'm doing a bit of research.