Regarding Voodoo2 with SLI, if you're looking for identical cards, it's easier to find with other brands, but Diamond Multimedia is the most difficult.
1. The PCB boards come in multiple versions: A, B, C, D, E and blank.
2. The vRam varies between Silicon Magic, Mosel, EtronTech, and in many cases, there are cards with mixed memory on a single card.
3. Some cards may or may not have external resistors. (There is one on your card)
4. Previously mentioned 8MB and 12MB variants.
5. If you look closely, the PCI gold finger also vary depending on the version.
I will check my Diamond voodoo2s later.
However, the chances are quite slim.