Why bother. For less that $140, you can not only get the guages, but also have someone do it for you. I plan to send mine in during the July 4th holiday holiday (won't be driving my car much).
2 members on this forum do this. The first is "CRHENKEL". His email address is
CRHenkel@aol.com. His website is:
http://hometown.aol.com/crhenkel/myhomepagebusiness.html
Another member who does these and sells them on ebay is "ronald_m". He sells his on ebay under the name "mbfanatic01". His email addr is
mbfanatic01@aol.com