Okay, after a bit more research my theory is as follows.
The existing red b1 valve currently in the car has the older style 2 spring configuration (see 2 - 3 spring train side note below)
My guess is this has now been replaced by the 3 spring train for better shifts, hopefully the yellow carrier will fit also, if not it may be a case of changing out the springs only - most of the upgrade kits featured above offer this option for either 2 or 3 spring set-up
Reading various articles and notes above, a lighter spring will result in softer 1 -2nd shift.
In terms of putting the springs together, please see below pic. We may be able to swap out the end cap (right of pic) if fitted to original. Also, with regard to the 'yellow' comment, the reference is almost certainly a spring as opposed to the carrier colour as originally posted.
