The difference probably has financial reasons; the regular card needs 'expensive*' push-pins, 'expensive' sticky thermal pad and 'expensive' holes drilled in the heatsink, whereas the other card only needs thermal glue.

_{*One push-pin is not expensive, but if you need ten thousand of them...}

I have only one Voodoo3 without holes in the heatsink and it's PCB is dated 16th week of 2000. All the other Voodoo3 3000's with holes are older, from first quarter to fourth quarter of 1999.

Yes, that is possible. My 'undrilled' Voodoo3 has a 'Made in China' sticker. Also noticeable is it's orange capacitor rather than the regular solid state cap. See thandor.net - Voodoo 3 3000 AGP for pictures .