Hippie Chris, the folks at Bear Archery are pretty good at answering questions on recommended brace heights on even older Bear bows. Try emailing them.
I would suggest starting at about 8 and 1/2 inches. Shoot a few groups listening for sound and watching arrow flight. Adjust the brace height up and down and look for differences in arrow flight and quietness. Adjust the brace height in the direction of best arrow flight/quietness until these characteristics get worse. Work the other direction until things get worse again. You should find the optimum brace height between the extremes fairly quickly.
Good Luck!