Gauges are getting hard to find, especially considering that they are
year-specific. I'd suggest watching eBay, checking with vendors that
service Corvette gauges, posting a want ad on Corvetteforum.com, joining
NCRS and checking their newsletter ads, checking with vendors who also
deal in used parts (ie, Corvette Central, Paragon, Crane's, Tracy
Performance...), etc.

I think some Corvette gauge repair specialists may be able to reface a
midyear gauge to match any other midyear.

Here's an eBay search for you to try: http://tinyurl.com/8ao6t

Here's a search on eBay completed listings, but I think you may have to
sign in to eBay first in order for it to work: http://tinyurl.com/792qy

Good luck.

Here are the best reliable source for spares in my book.
You could do it through ebay, but think about it, a gauge is a
precision instrument, what if the person auctioning it is trying to get
rid of it, or what if it doesnt work properly ? Atleast on these sites,
you have a return policy.

http://www.zip-products.com

http://www.ecklers.com/

http://www.westcoastcorvette.com/ (some nice accessories)

Best eTar