Just to clarify / correct my last post, the rule more exactly states that cars of period F (01/01/62) onwards can use 'the original seats', but if they are changed, it must be for FIA homologated (lifed) items. For earlier cars (Pre '62) it is recommended, but not compulsory.
So in theory you can change an original seat in a 1959 car for a non lifed modern one, but not do same with a 1965 car. I think any vagueness in the past was in the definition of 'original seats'- did it mean only those fitted from new by the manufacturer, or include aftermarket but period as well.......
I need a drink.
