I think Eau Claire runs an “any three karts” class if you can find some buddies. If you really watch to stretch their legs you could run road courses with CES and run the unlimited class. Usually there is some pretty fast machinery out there. Twin cylinder 250 superkarts for example.
Closest track is Blackhawk Farms which has a race in June and one in August. You could run up on the banks at Gateway in May too. KZ is good for about 119mph there, dual TAG should be good for 130 I would think.
CES schedule is here: https://www.kartpulse.com/championship-enduro-series-ces
I might have video of your kart from around 2006 come to think of it..
November 15-19, 2017
Las Vegas, Nevada
SKUSA SuperNationals 21
2018 Events TBA