No Colin, draw the torsion bar out to the back - that will leave the operating lever loose on the centre of the torsion bar, making it easier to work it off the pivot tube. You will then be able to work on clearing the rust from the end of the torsion bar (rather than trying to draw the lever over the rust, thus loosening the fit on the splines).
With regard to re-assembly, keep the torsion bar the same way round - i.e. dont turn it end for end. Presumably, you already have the bike on the stand. Put extra blocks under the stand to get the rear wheel high enough that you can feel the free movement in the other torsion bar, i.e. no load on the bar. With the bike lifted to this height, it should simply be a case of sliding the torsion bar back into place. When the bike is back on it's wheels, both torsion bars should be taking an equal load.
Eddie.