Top-up insurance

[zertec]

I have a particular problem.
I am buying an old Ferrari in Singapore.
In Singapore I can only insure it 3rd party as it is over 10 years old (a situation that seems to be peculiar to Singapore).
I would like to cover the value of the car with additional insurance that would obviously have no 3rd party liability.
I therefore need a broker or underwriter to cover this risk at a sensible premium.
Does anyone have any contacts in the market who can help? The normal UK motor insurers are not interested.
The car is a 1983 Mondial QV with a Singapore value of S$140,000 (just over GBP50k). I can supply all other relevat details on request.