Does it just squeak at the bottom (or top) of the travel when you compress and release it ? I seem to recall having something like this when I replaced the seals and put progressive forks springs in my R65 also, though I ended up changing the level of the fork oil (I think that I added a bit more than the ~210cc but can't recall how much).
Don't go crazy with the fork oil though - how much did you put in ? Perhaps adding another 10cc or so might stop it ? After adding a bit more oil, my fork would still squeak on occasion if not being used for awhile, or when hitting a big bump, but it now no longer squeaks. Maybe enough oil film finally made it to the inside of the fork seals after a few dozen miles . When putting it all back together, did you bounce the bike with the front wheel on with the pinch bolts/fender brace bolts loose to make sure that there isn't any pinching in the sliders ?
Apparently if you hear rattles/clunks of the spring, during fork compression, you could try putting the spacer at the top of the fork tubes (on top of the spring) instead of the bottom of the spring down toward the slider - if you can get that sucker back up outta there...
