Hi Grumpy,
What you have suggested is exactly what I intended to do as that was the sole purpose of acquiring the two electric units and the one knackered 17 inch twin railer. They have no real value apart from parts that are shared with the petrol units as the actual chassis's themselves are of no real use afterwards, unless someone wanted to convert them back to petrol model usage which would be a reasonable amount of work and as such it would be easier to find a petrol unit in the first instance.
I was originally thinking of getting the new solid top decks made offshore and make them available as a conversion kit, but time is the essence I guess. Actual viability of the project would also have to be in the right direction to do it in the first place.
Cheers,
BB.