Hi,
Whilst you’re correct that brackets without ac are more common than ones with ac here - ac was a very, very rare option here as it was pretty expensive and the weather back in the 1980s wasn’t hot enough to justify it apart from one or two days a year - the power steering setup for an early car was also a pretty rare option and finding the early car specific parts now is difficult- I helped a friend add powersteering to his early car and it took ages to find them (bracket, pump and extra pulley that bolts onto the front of the engine).
We nearly bought the parts from this guy in the USA who appeared to have quite a few of them, but then a setup appeared for sale in the U.K.
http://forums.turbobricks.com/showthread.php?t=344787
Cheers