New to forum, all advice gratefully received, sorry if this shouldn't be here.

Question about the regulations I do (and more importantly don't) know about UK non standard cars.

Answers from UK only please, this project will never be used outside the UK.

Pre 2000 petrol cars - do not require OBD, True?
Pre 1997 petrol cars - do not require CATs, True?

I'm looking to buy a small boring (1000cc or less) car cheaply and fit my own injection/ignition management. The reason is to have a standard looking car that is slow and economical for the daily commute whilst knowing that it won't become a write off overnight due to expensive ECU / OBD / power steering / ABS / Airbag failure.

I have some LPG conversion bits left over from other projects so may want to use those.

Can any 15 year old car still go on 'classic' insurance and how fussy are they these days when it comes to after market (power reducing) ignition/fuel mods. << please only answer this bit if you have had cheap 'classic' insurance YOUR SELF for a basic low power car.

Any quick advice about suitable years and pitfalls gratefully received.

I had hoped to go for old junk with small engine (2CV etc) but find people pay real money for that s***! So far the most likely candidates are old Nissan or Fiats...

Thanks again