Full marks for David & Richard, thanks.
Although AE is the right tool for this job, I think I’m going to have to do it Old School as per David’s suggestion.
My only hesitation was that I couldn’t find a way to Smooth the keyframes in the ‘Center’ settings [as you can with the Scale setting, hence wanting a plug-in.
But a short test actually provided some good results, so thanks for the suggestions gents.
Wayne