If it was legal to would you underwrite them yourself ?

just a thought
It is legal but the money required is serious. When I worked for a big multinational thats exactly what they did . They self insured their car fleet using Eagle Star just to administer it and deal with other parties.But given that a serious claim can cost £10 million, you can see why only Abramovich is likely to self insure his kids Morgan 3 wheeler.
On a differnet topic, when I said the trad was a business dead end I wasnt being critical of the car at all. Seems to me that for an old style car to be popular, a repro car if you like, it has to tap into potential customers who can relate to it. In most cases but not all it has to evoke memories of youth - what you wanted when you were a lad. And as time goes on, people's youth memories move with them. Whats more their expectations move on too. The Morgan Plus 4 was a car of my youth along with the TR4 and the MGB and the Healey 3000 ( seen the price of one of those recently?

) so I would like one now I can afford one. My son would not consider one - he thinks of cars of the 90s.
So FWIW, I reckon that demand for the trad will fall as the pool of potential; owners ages and is replaced by people wanting more recent nostalgia.