280/350 SLC conversion automatic -> switch

Servus, I want to get a C107 soon. It shouldn’t be too expensive, I think of up to 7000 €. I’d like to have one with a manual transmission, but these are quite rare. Is it possible to install the automatic transmission and a manual transmission with a 280SLC or 350SLC with a reasonable effort? If I would do something like this, then I wouldn’t want to cut a sheet metal, say nothing to destroy, so that the conversion could be undone to 100%. If that’s possible, what would you need? Gears and pedals, clear, but what else? Does the rear axle and the cardan shaft fit …? Servus Mario