Thanks but no replies are now required, the wheel came off with a bang after I heftied up the pulling apparatus. When it finally came free I thought something broke because there was such a sudden separation of the wheel and a considerable noise. The penetrating oil didn't have a chance because of the way the steering shaft is machined. The culpret was rusting of the wheel metal where it fit up on the tapered shaft beyond the relief behind the splined section of the steering shaft. The metal in the wheel had tightly fused to the tapered shaft. It's all history now.