From my own experience working as an instructor at the College of Knowledge,a few years back, you needed to have held an Ozzy rating for the discipline to be taught i.e. Tower / App or En route. Straight from UK you wont have this experience so I doubt if you will be considered.
On the other hand you may be able to apply as an overseas candidate for a controlling job; not sure of the age limit but we had an ex RAAF guy who was 52 on a Twr /App course. Feel free to PM me.
Rgds
BD