Thanks for the link. Unfortunately, I'm not in the US or Canada, but this at least shows me what I'm looking for. I notice that there are a whole range of spacer widths available for the Granny ring ranging from 2.2mm up to 8.3mm How does one know which width to choose? Is there a formula, or do you just have to eyeball it?

[QUOTE=BTW, have you contacted FSA? They will certainly have the required parts available.[/QUOTE]

Yes, about ten days ago, but no reply so far.