Yep, it is a Mk VII. Looks to be in very nice shape.
If it was a Mk I it would have teardrop shaped safety levers. The hook shape is the Mk VII style.
It will be 44 only. You can not swap on a 50 AE barrel. So just keep that in mind if you were thinking you could put a 50 barrel on it.
I used to have a 44 Mk VII for years. I love it and it was fun to shoot. However I really wanted a 50 cal, so I ended up selling it to buy a 50 AE that also came with a 44 barrel.