This past year at Ford Carlisle, I ran into a small vendor who was getting out of the business. He didn't have much, but I did manage to get a binder that is literally 6 inches thick that contained a complete set of TSB's from 1969 thru 1973. It contains all Ford's TSB's from that era, not just Mustangs. A bargain at total cost of $31, could not pass it up!
If you have a special need of a particular one, drop me an email and I will copy / post it on this site. I will as time allows, go thru this massive book and find / post ones that pertain to just the 71 - 73 Mustangs.
Maybe the site manager can direct me as to where is the best folder to upload these up to.
Mac