No, not a 7A, it's a No.8. Something went wrong between taking the pictures and editing them into the pages today - if you're really after a 7A, go and look at the No.8 listing, otherwise read on.
Castings for a Stuart Turner No.8, the next size up from the 10H. There's a picture of a really super one on the Stuart Turner page here, from the look of the fence in the background, I suspect I took it a long time ago at the home of a great Stuart Turner expert (and thoroughly nice chap to boot) then resident in Hampshire - he'd got a really nice example of just about everything Stuart's ever made.
If it looks to have rather more castings than you might expect for a single cylinder engine, one pair of connecting and eccentric rods actually belong to the 10H currently listed.