Stumps.
Is a 3110 or 3111?
If memory serves the Kort should work out at 100mm for 1/25 Scale. Simon at Propshop does a 100mm Kort and a 97mm prop to match it, he also does shafts
perhaps you might get discount if you buy everything from him.
Id estimate the hull dimensions at length 48 x 16 beam
You have plenty room in that hull for any type of motor
I’d have a look for some car blower motors cheap, don’t pull mega amounts of amps
and designed to last years.
There are Bosch one’s listed on
Alexander Engel submarine website
180watts
3800rpm
40ncm torque
12v nominal
Now the T12/24 I’ve never used them so can not comment on them
Small compact unit, however there is very little spec available for them
Rpm i think is 4600rpm that’s all i remember.