Thanks davegt.
Well, I managed to get this sorted - probably not the most efficient way but I'm just glad it's sorted.
I managed to get a couple of seats off the forum for a competitive price in the hopes of doing a base swap. As I was a bit more aggressive taking in dismantling these seats I found a better way of taking off the side panel and unscrewing the seat. I was therefore able to "dry run" a gearbox swap for the recline motion, so instead of doing a base swap I just able to confidently perform a transplant op.
Et, voilla, a repaired passenger seat (misses will be pleased) and even a spare seat (I have another project in mind for that).
Thanks to all for their help
David