wow, you have bellows pliers?
where did you locate them? i have been searching all year, since i started collecting rollermatics.
yea, pb blaster is available at lowes and home depot.
my 1-18 removed easily. just be sure not to try to loosen that nut without holding the shaft it screws onto tight with vice grips. if you don't hold it the only thing keeping it from turning with the nut is the keyway which holds it in line in the spin shaft, this will shear off easily causing you more problems!
that shaft has to be held firm. i bought the biggest pair of vice grips i could find and also put a peice of iron pipe over the handle of the vice grip rather than allow the vice grip to push against parts of the washer. especially don't let it rest against anything plastic or easily broken like pump parts, hoses, etc. i keep this 4 ft. section of pipe just for anchoring the vice grips when i'm removing shaft nuts. i usually brace it against a wall or sometimes my foot. then i use a socket with a long arm extension on the handle and very gently start to loosen that nut. all but one have come off easily. on one of my rollermatics the shaft itself loosened from the coupling which is inside the jet come area.
the rollermatic shaft on all of mine are a 2 part shaft, held together with a coupler. the 1-18 shaft however does not have this coupling, it is a one peice deal so you should be ok.
i would bet they eliminated this potential problem when they designed the later 1-18 model, wish the rollermatics had a one peice agitator shaft. i still have a jet cone with top nut intact and a small stub of a coupler sticking out it's bottom end. still not sure how i am going to loosen that nut. am soaking it in pb blaster for a couple months while i take a break from it.
have fun