Just be aware that their are 2 different size "Midland-Ross" Boosters. They are also fairly hard to find as a rebuilt unit, and to get parts for. Their is a 6 1/2 in, and a 7 in, or 7 in , and 7 1/2 in. I can't remember right now. The parts are the same, except for the 2 main diaphrams, one of which is metal and rubber, and the other, that is all rubber. the metal/rubber one is the one that usually cracks. These are the parts that are different in diameter.
You do not have to disconnect, or take all the brackets off, just disconnnect the rod on the upper bell crank, with cotter pin, then remove the 4 bolts/nuts from the master cylinder, in front of the booster, making sure your master cylinder stays level, ( you do not want fluid leakage) , then remove the 4 bolts/nuts holding the booster to the bracket, the booster is now loose. Get a good tube of "Silicone Grease". You will need it to reassemble the new parts. The hardest part of the rebuild was getting it back together, with no vacuum leeks. I used a dead blow hammer on the V band, and also vacuum from another car, as you tighten the V band bolt and nut, (hand vacuum pump was worthless). Remember to use the silicone grease, on all the parts, at asembley. After asembly bolt it back in. I did not have to do any adjusting, as i didn't change any adjustments.
Heres a pic of mine after I reinstalled it, all cleaned up and painted silver. On the left top is the only rod to disconnect, it has the cotter pin in it.
I got my rebuild parts from "Harmon Classic Brakes", in California, 1-818-290-3738, or harmonclassicbrakes.com Very help full.
barracudadave67