My Mk1 right front leaf spring suddenly went soggy, so today i thought i could use one from my mk2 which is lying doing nothing. Anyway when i`d got both springs off i saw the MK1 is more curved, and a couple of cm shorter -probably due to the curve. Also the MK1 front bolt is 19 mm diameter, the MK2 is 18. so i thought OK might as well try the MK2 on anyway. It did go on , but didnt give any more height to the wheel arch than my soggy MK1 spring. So i greased the bushings and put the MK1 back on, and it seems to be OK again - could it have been those bushings were causing it to stick somehow ? I havent had time to drive her around yet, to see if it sogs down again.
PS when loosening that front bolt there is a lot of pressure on the spring, even if its jacked up. So any budding spring changers - be careful of your fingers when removing that bolt.