Right then, seems like the hard work has been done here, but I'll chip in anyway seeing as I raced and own about 6 pairs still...
Yup, they def look like GT Pro's Santa Ana 1982/1983. They will be unstamped and unknurled. In 1984 sometime GT started stamping the bars on the left back downtube with the gt logo and knurling again appeared late 84/early 85. When you said 28" wide by 7" rise I though UhOh... as GT Pros were a stock 28x8.
I see why..you are measuring the rise to the crossbar...this is wrong..the rise is centre of bottom tube to half way up the grip tube, this will give you around 8" rise.
Top bars. Pretty much the pro's choice of race bar for many years. GT's design remained the same even into the early 90's except for introduction of an oval crossbar.
They could have course be early Patterson Pro Bars too..... they were identical and made in the same factory. If the chrome has any peppering then take a look on crossbar and back left tube to see if there is any "clear" chrome where the GT decals were at one time... its not a definitive way of identifying but it is a help in certain situations.
Someone has been reproing these very bars over the last couple of years. So those thinking of buying so called NOS, just beware. Far better something like yours and refinish them for 100% good old school peace of mind...
I just sold a set here.. £40