In reply to Tigger:
welcome? to the club Mike, I think my tight, confidence inspiring Miuras also exacerbated the problem. They are sadly relegated to the cupboard.
Find the right shoes. I found my heels comfortable in Scarpa Helix's (or at least the earlier version). They seem to have a thin soft heel rubber that conforms to the lumps.
And avoid too much heel hooking......
Otherwise heel pads covered in gaffer tape worked in my mountain and ski boots, not so good in shoes though.