I had a 1986 TT350 and in those days, you could get a title with an off road bike. Today, you can do the same thing in Ohio with a "change of body affidavit". What I did, was get the XT350 brake light switches (the tail light is a dual element). Adding turn signals would also be a snap.
The TT350 was a much lighter, better suspended bike than the XT350 (which I also owned) and I wish I still had mine.