ST2300, given the apparent tail heavy issues- there is no substitute for displacement... Magnum now makes a 1.20 I believe not sure of the price tag on that one.

An underpowered warbird is, in my opinion, one of the most difficult RC airplanes to fly. And the "Jugs" is no exception- it is fat and needs a bit more power than suspected by many... Get at minimum a .90 (ST) up to 1.20 2 stroke, this will help the balance issue and give you power in case you need it -

I love my Tower-75 but for a 60 sized WWII airplane? Nope...