Adj. azimuth for Black Widow tonearm

Recently purchased a Technics SP25 with a custom plinth and a first version Black Widow with the aluminum arm and carbon/resin headshell. The cartridge sit slightly off perfect azimuth so I made paper shims to compensate. Where the headshell mounts to the arm there is a set screw and it is slightly conical at the end where it contacts the arm. It makes sense that this is used to secure the parts but loosening or removing the screw does not allow the shell to move on the arm. I sprayed some Deoxit in the hole the screw came out of but have not tried and heavier penetrating oils. Any suggestions from those that know this arm?
After trying a couple of different penetrating oils I went out and bought A NEW can of PB Blaster nad applied some to the hole where the set screw came out of and where the arm and the headshell meet. Let it sit for a few minutes and still did not budge. About a half hour later I cleaned up the arm and decided to give it one last try and the headshell moved with a 'tic' sound. PB Blaster to the rescue.