Interesting, thanks Ron. Both the James’ I’ve got have the spark plug on the right (going forward) The last time I was in Villiers Services (2017) they were rebuilding a 9D and that was the same. As you say it doesn’t make much difference.
The gearbox outer casing was wrecked on this engine, so I had to fit what I could get, although it didn’t have any numbers on it.
MS