Not a Mk 19 but you have already mentioned the mark so I'll keep it locked for you.
If it's of any help the photo was taken at Goodwood in the early 1960s.
OK, so it's either a Mk 4 or a Mk 6. I've studied pictures of both and the only one I can find with a front and lights similar to your puzzle car is a Mk 6. However, the Mk 6 was only made in 1964/5 whilst the Mk 4 was built in 1962/3 and since you say the puzzle photo was taken at Goodwood in the early 1960's that would have to make it a Mk 4! If I'm wrong then it's not going to take a genius to work out what the correct answer is...!
In all 26 Mk 4s were built in 3 versions, the majority of which were the standard model, but 2 or 3 were built for road use as the Mk 4T; they had steel wheels however so the puzzle car is not one of those. There was a slightly improved Mk 4 in 1963 with lowered engine and gearbox together with minor suspension modifications.
The Mk 6 cars were a development of the Mk 4, and looked virtually identical, so it's not really possible to distinguish them just by comparing pictures of them. There was also a Mk 6A but again only with mechanical changes.
I can't actually find any mention of a coupe version of either car!
