Yes it is a trackday pic, the "All Triumph Trackday " organised by the TR Register - Great fun, there is another coming up at the end of June.
I only do trackdays and run-what-ya-brung Dragstrip public trackdays. MSA and FIA approved stuff being too expensive for my almost non existent budget! In general, they don't seem to offer much track time for your £100+ per day plus fuel and travel expenses, 3 or 4x2 minute ish runs up a hill or 3-4 single laps of a circuit doesn't strike me as good value! Plus very few official events welcome my b'stard hybrid of a car. Not to mention all the "must have" stuff they insist on, fireproofs, special helmet, shoes, roll cages, etc, etc, blah, blah, blah. And of course, laminated glass!
The last ATTD i did, I got 90mins of track time in 6x15 min sessions at Coombe, and could possibly have had 1 or 2 more, well worth the trip for £110! And Shakespeare County Raceway will give you unlimited runs for £20 a day (subject to queue length and weather)
The Carledo is running ordinary common or garden late Sprint hubs with 7/16" Studs at 95.25mm PCD(3.75"). The wheels are MGF (NOT TF) which obviously match! TF rims and your ZR rims are, IIRC, 4x100, so no they won't fit, not even with a big hammer!
I do take your point completely about the amount of track time you get for your money - but I've never really fancied a track day, I like the whole thing of measuring yourself against other people and competing against them. My hillclimb/sprint car is only a 1.4 - but on occasion I can give the slower 2-litre cars a scare
which is very gratifying
thankfully not had too many moments leading to a swift change of overalls
With the Carledo you would have to run in Formula Libre and yes, they can be a bit picky about some of the mods. For me the roadgoing series production class is the best of all worlds - I'm slow so I get more track time for my money
and the admin is less, no need for HANS and the dedicated helmet, new belts and new seat that would inevitably also be required.
Thanks for the tip re MGF - I assumed they were the same PCD as the TF and R25/R45/ZR/ZS. Hmmm, shopping time maybe