[wilf leek]

Paul - I can't say for sure if your valve seats would be OK for unleaded. Has the engine been rebuilt at some time? I would guess so, and it would have likely received new valve seats at the time, which should be OK.

Untill you get a more definitive answer from the guys here, you could use Millers VSP, which is THE additive to use for engines which need leaded. Also gives an octane boost.

Metaline - nice car. Where abouts are you in the UK?

Edit: PS - don't bother with LRP - it's useless.