I had hoped that my 97B would fit in the El Paso Saddlery 1942 Tanker that I already had for my 1911, but it was a bit too small.
Nobody seemed to make a M3 or M7 holster specifically for the 97B, but the M7 available from World War Supply was reviewed as being a one size fits all holster, and one reviewer said his 97B fit, so I decided to give it a try.
As it comes, it has kind of a tear drop shaped opening, and I couldn't get my pistol all way in, so I put about 1/2" of warm water in a container big enough hold the holster and put the holster in face down. I held it in place for 2-mins, making sure that the back didn't get wet as I only wanted to stretch and form the front.
After shaking off the excess water, I inserted the pistol. The pistol was in two ziplock freezer bags to give me a little bit looser fit after it dried. I pressed the leather around the trigger guard and under the dust cover to form it to the pistol.
Here's the opening after drying:
The forming:
Fits like a glove!