If you can hunt one down, TTW (Turntable Weights) made one especially for VPI 'tables. It's solid brass with built-in bubble level and spindle hole threaded for VPI. IIRC, I paid $99 for mine, but I don't see them on the TTW site anymore. You might contact them directly, or look on Audiogon, eBay, etc.
On my Classic I, it works as well or better then the supplied clamp,perhaps giving more 'weight' to the low end.
Happy hunting,
Mark