Got myself the manual boost controller from http://www.dawesdevices.com. It works pretty well so far. The hoses that it came with were too small to fit on the wastegate and turbo, so I had to buy some vacuum connectors and some larger hose. I managed to get it all together and am pleased at the results.

The "stock" boost controller setting was (surprisingly) at 10 psi! After a couple adjustments and test drives, I locked the boost in at 13.5 psi (0.9 bar, upper limit of factory spec) and the ALDA was turned 3/4 turn counterclockwise. Acceleration is much stronger, and the car continues to pull strongly at 90mph. I have the 85mph speedometer (1982 model) but I removed the restriction pin after the 85 mark. I have not clocked my "new" 0-60 times, but I would estimate them to be about 10 seconds.

Some smoke prior to full throttle, (as was before the boost adjustment) but no noticeable increase in smoke. Overall I am very impressed. Please let me know if you are considering the procedure, and I can elaborate on the specifics. (ie, which vacuum adapters and connectors you will need.)