I have a Tony Kart Racer EVXX with BS7 hand brake roller for sale. It has M4 bodywork and TK graphics. Tillett XL seat and Douglas wheels. Most recently used with a clone and actually very little time on the chassis from new. It would work great for TAG/Rotax or TAG/Rotax Masters. To convert to 4 wheel brakes all you need is a brake line kit. $1500 OBO PM or email me at email@example.com if you are interested. Kart is located in SE Mighigan.
Its an OTK factory system used in KF. It’s not legal in most series. It is fun to play around with though. You can easily convert to no front brakes or 4 wheel brakes with simply adjusting brake lines, etc. The hand brake setup simply controls the front brake sysem independently. So, you get the best of both worlds.