Wow......C49's. These were the latest thing in tyre technology in about 1964, even though they were still cross-ply. So special they rated a mention in the above 'works demonstrator' ad. My Dad had a set on his MKI 2.4 Jaguar, fitted by no less than Wally Darrell, at his ACE tyre shop in Christchurch. The 2.4 didn't have the sort of performance to test these things out, but they seemed ok for an odd blast into the countryside.