I am not certain, someone else may respond with a certainty, but from the ReadMe on page one here:
Mikhayl - Type IIB Uboat
Stiebler / Tomi_99 / Mikhayl / Dietrich / Flakmonkey
- Type XXIII Uboat from NYGM
I have no idea if those credits would include the interiors, but the only interiors I could find mentioned were for the VII & IX boats. But, there is a lot of SHIII in there...