Swapped the springs over today. New ones are shorter in length but have more coils on them which coil closer at the top. Went in easier and all looked good until I jacked the car down and it's still way too high! I'm thinking now that I just bought some more mk3 springs even though they said it's suitable for a mk4, or perhaps there's variation between models. The listing said they have coil lengths of 261mm. It's marked as compatible with Ford parts 6146156 & 6146157.

I can also see there's some springs listed which are 227mm in length with ford part 1613228. The parts for this number I find are also listed for Mk3 & Mk4.

Priobably it's the 227mm ones I need.