HOW do i get my frozen R calipers unstuck from my rotorz? Options

[Schump]

I have a '73 2.0 i'm parting out, and my rear calipers are uberfrozen to the newish rear rotors.
anyone have a good way to get the pistons to slide back through their original hard as hell rubber seals and unseat so they'll loosen up enough to remove the calipers?
i've already loosened the e brake adjustment nut and of course loosened the bleeders! (IMG:style_emoticons/default/WTF.gif)
thanx a lot
914 addict
soon enough to buy another one...w/o factory rust for a mutant V8 mod....
after I turbocharge/intercool/big brake etc my just bought $500 88 jetta Gli w/ factory recaros etc... (IMG:style_emoticons/default/rocking nana.gif)

[Schump]

still no luck BAAARGH!!! (IMG:style_emoticons/default/WTF.gif)
I tried doing what yall suggested, but alas, the gods that created the 914 were hovering overhead...they saw the rot in the rockers and jackpoints and the lower dog legs and said..."WAIT...we should have added MORE to those r calipers!...yeah, the adjuster screws, we didn't completely secure those...Let's get out our microscopic MIG and weld them in place...from the INSIDE of the caliper!"

ok, so i have had issues with these calipers before. I believe this is actually the one that froze up on me in the winter of 2001 as i remember the car had "a bit less power" and i could hear the pad grabbing. one of the last times i drove the car, i could not find a ride to ski team practice, so 60 miles later west of blacksburg i was in BFE, West By God Virginny...Ghent 2 be exact. at WinterHole, a ski mountain built by a bunch of drunken rednecks in bulldozers!...hmm, why cut a nice steep trail here on this natural hillside??? naah we can't ski that!, let's instead pile up 2 stories of dirt to make a "freeway" to get those who can barely stand back to the lift to the lodge, of course, if they catch an edge, they go down a HUGE embankment that's 20 feet high, and end up in a dense forest, they WON'T get hurt that way!!! (IMG:style_emoticons/default/chair.gif)
anyhow, this caliper was siezed cause the rotor was really hot, i spit checked it and MAN was it warm.
so back to teh task at hand...

Previously, a long time ago, i had tried to loosen the outside 4mm allen bolt that adjusts the pads. it didn't want to budge and it split like the top of a castle nut so that now when u try and use a 4mm allen (even a "true 4mm" aka snap on T handle) the allen spins....some reverse engineering...
well...if i spin the adjuster nut out enough...i can get it to hold the allen bolt "closed" around the allen head.
nope.
i turned too hard, mo fo sheared off w/ my 13mm wrench
my next sugegstion is this...I have about 2.5 threads showing out of the caliper.
take a bolt and double nut it, with the 2nd nut showing 1/2 it's threads sticking out past the end of the bolt that's the same thread pitch as the 4mm allen. double nut to prevent nut from spinning on bolt...duuuh!...old trick i learned with the Formula car and racing...and screw it on hard, more penetrating fluid, this time some heat from a torch, tap the caliper with a hammer a few times as well as teh screw (already done)
and try again
i have not yet added the torch
been busy polishing my front and rear '72 chromies bumpers i'm selling....
any suggestions from teh peanut gallery?
you guys are the best, thanks for all the honest help so far, still have to try prying more w/ different sized pry bars and maybe leave 1 caliper bolt in the trailing arm and try prying the bottom out, if that doesn't work, heat the caliper and .....pray!
then sit there and (IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/popcorn[1].gif) for a while till Fe2O3 gods look kindly upon my actions....