SVP 80 (or so)
This is a 1968-70 model and yes it does have the insulated tank. Robert, Michael, and I all have one (similar models). Mike illustrated his in a couple of months ago in an Imperial thread.
These do have an inner tank, but it's not insulated in the traditional sense. It has some cardboard inserts around the tub to keep the outer wrapper from bowing in an out. The air space between the tank & the wrapper acted as a sort of insulation.
It is a very powerful dishwasher that cleans very well; this model features the rare Delco Turbo pump. Hope someone can save it.