I don't know how far you've gotten on this project, but... My '76 S3 109 came with power brake booster and single pot master cylinder. I've since added a dual master without any frills (no shuttle valve or brake failure switch) several years ago, I had to get it from England, just for the 109. Be aware (if you aren't already) that you my have to notch the wing top to fit this all in. Sorry, for the late reply, just haven't been keeping up with posts. Oh, just whip up a bracket and stick it on, it's not a critical part. Unless everything has to be Land Rover stamped for a 100 point restoration.