Here is one of my favourite models: Airfix Mk I, which I converted to Mk II and added a small diorama, using two Airfix british infantrymen and old Matchbox diorama base.
Were you using an old kit with grousers added, or are those aftermarket tracks? They're not the soft rubber tracks that Airfix supplies now.
Incidentally, everyone likes to complain about the inaccuracies of the Airfix Mk I: has no-one else noticed that they don't sell a Mk I (or not any more, at least), it is sold as a "WW1 tank"? Perhaps they should re-brand it as "Mk II", it would surely only be the rivet-spacing anyone could really complain about?