1978 7060 powershift brake?

Backstory...

We got it with a ranch and had no idea what and if anything was wrong with it. We got it running after changing the fuel, filters and getting the metering sleeve loosened up and attempted to move it, steering didn't work either and discovered a spool was installed backwards and an orfice disk was missing, fabricated a new plate and steering, brakes and hydraulics are 100% now 

So Attempting to move it we discovered we couldn't shift the range into any gear, it would just grind, had to stop the engine and restart in gear, then it would move slowly forward. Anyway it had no reverse and no 1st and second, 3rd was slow applying but would kill the engine and so would 4th, 5th and 6th. Checked all pressures and everything was within specs except brake pressure, it stayed at zero. Adjusted linkage, no change, pulled valve, dismantled, reassembled, used air pressure and check the plate movement of the clutch packs we could see and listened for leaks and everything seemed good. Interestingly the drums turned easily by hand and we stared the engine briefly and there was no dragging with the range in gear and it was easy to shift. So we reassembled everything and it was exactly the same as before. 

So I've split the tractor and pulled the powershift unit right out of it. What I've discovered so far is the six half inch bolts that bolt the 61T gear (70267719) to B1 clutch hub (70267754) were all sheared off. The rest looks pretty good so far, there may be some warped and discolored disks and spacers. 

Anyway, I cannot find the clutch brake, what am I missing? Logically I would think it would just apply three or four clutches simultaneously to act as a brake (similar to Case powershift) but it does have a dedicated transmission brake test port so how does this work? I've been back and forth through the service manual and parts book and cannot find any reference to the actual transmission brake components for the powershift. 

Can anybody help clear this up for me? I have to be missing something.

Thanks.

I have one Allis, a 7045.  Mine is a power director, not a powershift.   I needed some HP, and it was hard not to chance $9000 for 150 HP.  Probably got another $5k in it during the first couple years.  Agreed on the cab, but it is nicely quiet in there once you get situated.