[Yosemite Sam]

Not so sure I agree with everything in all of the above posts.

I've seen a number of Quiet Line series tractors with internal brakes (not sure who put them in there, but they were there never-the-less).

I do believe that everything "hooks up" the same, internal or external.

And yes, there may be issues with external brake transaxles in round fender tractors (70, 100, 71, 72, 73).