Here in MN if the vehicle is over 10yrs old it's odo exempt and they just put in the base value instead. Carfax should show you progressively what the mileage was, but if it only had 1 owner, and a dealership has to report it when they buy it, you should have 2 refrences on carfax. Then again, it might've come up exempt. I know for lease vehicles, exery time you take it in for an oil change they update carfax with new odo readings. My truck has a 5 digit too, it's a bit confusing, everyone first thought i had a truck with only 12k miles on it, then they counted.

If it is comming up on 200k, that'd be just over 15k miles a year. Does carfax show any fleet registrations? I wouldn't believe that it only had 27k in 1998. I would believe 127k though.
EDIT: As i re-read i see the link for carfax. After reading it, it did have a lease registration, so i would say that the 127k would be accurate. (Since most lease companies make money on mileage per year allotments) And the newest title on there states exepmt from odo readings, yea, he tried to tell you it only had 98k on it because the odo says that... 5-digits suck for that reason. He didn't even have to tamper with the odo to roll it back.

Get the bastage for all he's worth. I know up here in MN truth in sale is quite a big racket. If they knowingly misrepresented the mileage, they're in a world of hurt.
Do you/are you having a new title issued to you? If so, all they have to do is slip up and report 98k on the title and blam, instant discrepancy, since they've already got 127k on the paperwork. I suppose the dealer could use the defense of "i just reported what the odo says, since it's 5-digits, it reports 98k"... But i don't think there's a judge in this country who would buy that.
I would say, pending the answer to a few questions, you have quite a leg to stand on. If the odo says (1)98k now, and it said 127k in 98, that's about 12k miles a year over the past 6 years, so whoever's had it, didn't drive it too much.