Yes as stated, leave the exterior.
I offer a refurbishment for my customer's..or a RAT ROD restoration as one put it, where we leave all visible components original, paint, chrome, etc.. but then still tear down the machine, remove all insulation clean up the insides, powder coat tub and inner works, restore bottle stack and shelves and then reassemble with new gaskets, electrical , insulation and such.. so it runs and cools like restored machine but still looks original outside ..
This is exactly what I will be looking for. Is it inappropriate to ask what a ballpark figure for this type of restoration would run?