speedo problems

[slick rick]

Started having a couple of problems, first is my speedo is all over the place, and flicks up to full scale even when not moving. Car is booked in to get fixed next week.

However, worse and probably related problem is that i've just driven 45 miles, but the Tuscan thinks its done 230. Does anyone have any suggestions for how i can get home at the end of the weekend without putting 1000 miles on? TVR dealer said once the milage is on the odometer, no way of getting it off

Rick