Springs n'd things

Hi all

apologies if this has already been asked

I've been reading up a bit on the mod for the Saitek yoke which initially used rubber bands  but which I believe uses springs now

As most of the stuff I've read seems to come from usa including where to buy these springs I was just wondering if anyone in the UK  has done this mod and where they bought them.

I have a couple of Maplin stores near me but not sure what size springs are required

many thanks for any advice and part numbers

cheers