Variant Artwork

Is anyone out there keeping track of variant artwork for each card
(for each expansion) ?

I'm way behind keeping track of these - I'm only accurate up to KWM,
and certainly wouldn't mind double checking my work anyway.

I've thought about using the card list at white-wolf. I could narrow
down the list of cards that have more than 1 artist, since I believe
that would represent all the re-worked cards. However, it doesn't say
which version they worked on. There are even some cards where the 2nd
artwork didn't 'stick', and they reverted back to the original
artwork:

Thaumaturgy, for example, got new artwork during the Sabbat set, but
reverted back to the original artwork for the Camarilla and 3rd
edition versions.

The reason I'm asking is because my spreadsheet keeps track of all my
card quantities by expansion (useful for trading) and the quantity
number is black if it's the original artwork. It's red if it's the
'new' artwork. I do this because in my display binders where I would
normally have a copy of each card, I like to put in a copy of the
variant artwork next to it. And to top it off, I always replace the
cards in the binder with the latest and greatest versions when they
come out (for errata purposes).

1) Has an artist ever redone his own original card, or has it always
been a new artist?
2) How many cards like Thaumaturgy are there?
3) Has any card ever had 3 different artworks yet, or is the max 2?
4) Has someone already done this?

Thanks,
-Terry

Haven't kept tabs on the number of such cards but I have set aside one
copy of each different card from each set, also including each reprint
from precons and such.

Back in the day when Orava used to compile lists from the net (when
internet accesses weren'rt as commonplace as nowadays) his lists also
included misprinted cards (RenagAde Garou and the like) whih i also
managed to collect. Unfortunately I think I haven't seen such lists
anywhere since V:TES came out so I might be missing some...