Sounds like the best solution would be a mobile workshop like my kit car group use for tour support. Mercedes 814 with a ramp inside able to hold a vehicle on the top "deck", so you can work underneath it. Fitted out with electrics, a workbench and tool cabinets, generator, compressor, etc. and a large side awning for extra fettling space.
Doing that with a 700 kg kit car is one thing, a 1700 kg Omega is a different matter.

It's still an expensive resource to maintain. We make it pay by a couple of members using it for commercial purposes when it's not required, and we also run several quite expensive tours per year for 50 odd cars, and include truck support in the total costs for the tourers. Added to accommodation, food, petrol, etc. it's not that significant, and we'd have left a
lot of tourers behind over the years without it. K series head gasket change between last orders and breakfast, in a hotel car park in the back of beyond in Italy, anyone?