For the road-going F1's, a good starting point would be these 4 threads -
Recap of Japanese F1 fleet
Recap of European F1 Fleet (excluding England)
Recap of English F1 fleet
Recap of the American F1 fleet
The GTR index sounds like a good idea, to get all the GTR's, short and longtails, still in use be it in roadgoing guise or track use.
As for the GT's, I believe there is 1 in Brunei, 1 in the UK
and 1 MIA
I'm not sure you want to include XP1LM in the XP list, the LM list or in the list at all, as it is displayed rather than used by it's owner.
It also may help to define the timeframe for 'getting used by their owners', as it can be regular like #020 and #06R for example or scarcely as in #021 and #19R (if #021 is the elusive F1 seen in Monaco)