Not a problem IMHE; if you are already a memeber of say the RAC, you can either add it to the annual policy or get seperate cover. To cover my similar aged Tiv last year for LeMans it was around £60, the previous year (less than 10 years old) it was nearer £20 .
Can you insure it on a classic policy, or do you need it for business use?
If so, try Carole Nash as they throw EU breakdown cover in with the premium. My 911 is 20 yrs old and they still cover it. Haven't had to use it (touch wood) but it's written into the policy.
Classic poilcy with someone like Heritige will do, I get mine insured therough them as part of PCGB and it includes PCGB trackday cover, garaunteed value and european breakdown cover. Mines limited to 3k/yr for about £440 this year.