Re:
Sorry change 30s for 10s above but they where the same target.
MAG30 and MAG20 where the first Mag forks. 1992 model. Different legs, crown and bushing setup without the negative springs etc.
But 30s where a non externally adjustable version, memory serves a long screwdriver and you could turn the flat head screw driver to do the same thing. Of course you had to drop the air and mess up the oil to turn it.
1993MAG 10 had the new internals and negative spring (and newer externals) but same adjusting method.
1994MAG10 adopted the external adjustment of the mag20/21 but just used a recess Allen key.
You can fit 95+ top caps on to these and vice versa to get the adjuster style you like.