..is supposed to be between a standard Meteor MK5 and a super Metor?

The reason I'm asking is because I've just bought a cheap, slightly shabby but perfectly serviceable (after a few parts) TH prefix Meteor for £15 which if I'm correct means it's a Super MK5, but I can't see any difference really between it and an ordinary MK5.

Should it have 'Meteor S' written on the tube for one (mine doesn't). Are the parts from a standard mk5 interchangeable should I come across some.

Would be grateful for any help or advice.