Update for everyone. Called Admiral. The agent was very helpful and together we sussed out that 370Z (base model) was not on their system. However the GT and Nismo were. Underwriters have refused insurance on the 370Z base model when this matter was referred to them yesterday.
If I had gone with the GT, I would be insured, and only paying 700 quid of insurance. So the only option for me now is to leave admiral and go with AXA for 967 quid. This is silly. Everyone thanks for all your help. Anybody who would like to shed more light on this issue please do so.
Feeling a little ripped off about this whole situation.. 🥲
edit: at least I THINK it's the base model. It's a 2020. Deep blue pearl. It's got the akebono 4pot brakes at front and 2pot at rear. Has rev match feature. However it's got no sat nav, cloth seats, 18 inch dark grey/gunmetal wheels, door handles are grey. That's about all I know that convinces me it's a base model. I'm actually surprised the base model came with akebono brakes. I thought it would only come with your econobox brakes, no rev match and no VLSD.
980 miles. Priced at MSRP. 1 alloy has chip+rash. Front wind deflector below the bumper has scrapes. Front bumper has 2 50p sized fine scratches. Chip on door handle and door. Intending to 2 stage correct and PPF the whole car myself. Dunno if I bought a poor example & paid too much