I have to admit to not knowing about TTRs until the one I bought came up for sale in a local ad.
My internet research led me here & you should know it was your enthusiasm for TTRs (& potential support) that help me decide. I had wanted a 4-stroke trail bike & liked the looks of the WR's but they are too much $$ & probaly too much bike since I am well on my way to old & feeble.
The air cooled, simple nature of things was also appealing.
Unfortunately the TTRs here in the US were sold as off-road so we'll see how getting it registered plays out. Vermont is/was lenient about registrations but things are changing everywhere.
I have been in contact with Matteo by email about his quest as he is only a few hours away & trying the same thing.