Flyingcope,
I assume that you are referring to ex-military types that are operated under CAP632 (e.g. Jet Provost). These are all Annex II aircraft that are flown under national regulations and require a UK licence and not a Part.FCL one (because EASA does not recognise the types and therefore does not issue a type rating). An Aircraft Type Rating Exemption (ATRE) is then required for each type. An initial submission is made to the CAA for a training exemption which must include the proposed training syllabus. Once this has been approved and the training completed a full exemption is applied for. An application for renewal of the ATRE is then required annually, and may be re-issued based on hours on type.
Whilst I admire and can understand your enthusiasm to fly this class of aircraft, unless you manage to gain significant experience of high performance, manoeuvrable aircraft then do not underestimate the amount of training that you would require in order to be issued with a ATRE. Good luck!