Yep, they changed around 1889, bit confusing , I have had large spline F reg Golfs, and small spline G reg. Whatever, the splined bit of the steering column is WAAAAAAAY bigger on the '89 onwards cars......looks to be at least twice as wide!!!!
Halfords are staffed exclusively by spotty teenaged mongs who only know what the computer tells them.
Persist, Mountney do list a boss kit suitable for your car......
Cheers, Mark.