The rubber linings (eoltas gummi as you refer to it) will not make an awful lot of difference because they are used to reduce the amount of distance the car lowers when it is heavily loaded (i.e. when you have full trunk etc.). In unloaded condition the spring will not have small enough distance between windings to make a tight fit for a spring.
a simple solution for your model is to use 2 mounting plates under the spring, i had this setup in my car few years ago. If needed, you can put a pipe of respective diameter inbetween the two for extra lift. In my case the lower plate was mounted upside down for some reason (see attached picture). And yes even if you use some extra pipe, you still need 2 plates, as pipe is not strong enough to be used as lower support!!!! (guess how I know ;-) killed 2 brand new shocks this way, as when the pipe failed it killed the chamfered edge of the shock, where the plate normally should go). This may look ghetto, but hey, 'it ain't ghetto if it works', right?
What lift do you need? if it is about 2cm, so use the same setup as mine in the picture. But be careful with the amount of lift as your shocks will hate hiting their upper limits, especially if they have a shorter strut insert than oem setup. This will kill them instantly.
Another more ghetto solution is to weld another mounting bracket (from your old shock for example), but this is a bit too ghetto for my taste. The advantage of it as it raises the rear end by extending the whole suspension by this hight and it does not extend the shock excessively. The disadvantage is that it is destructive, in comparison to adding an extra plate.
Can't check the vin as the car is too old, but it will not make any difference as we are talking about aftermarket setup now.
