I took the opposite approach with the dearly departed "Blue', my '84 R65.
Instead of trying to keep the front wheel in the air, I installed a Reynolds Ride-Off centerstand, which worked like a charm, was a breeze to operate, and kept everything very stable and "on the level". Mine was chrome, but here's a pic of a black one.

On the occasions I needed to get a wheel off the ground, which were few and far between, I'd put the stand itself down on a piece of 1x12" board and achieve the "stock" result.
I think I paid about $100 for the one I bought new on Ebay, and have seen used ones for less... [smiley=thumbsup.gif]