The O-Ring on the tick-over screw gets really hard with age and stops holding the screw in place so the tickover goes all over the place - up to about 2000rpm so thats worth a look

if you can turn the screw with your fingers its fooked

The boot on the steering column is meant to have a split in it, to help with fitting i suppose

just make sure its pushed in as far as it goes

Does the horn work when you're driving along - my horn doesn't work when stationary unless i rev the engine, no idea why but i had the same problem with a couple of previous mk1's so i guess its common.

this spring thing sounds dodgy!!! - are you saying you're shocks are knackered or are you talking about a spring on the sunroof (how would that affect steering?)