It looks like I may have the wrong brain installled (story of my life).
The same chip as mine is on eBay advertised as "748R chip for 45mm road cans"
http://cgi.ebay.co.uk/Ducati-748R-St...3A1%7C294%3A50 The same seller also has a chip for "748R 50mm race cans", so subject to clarification that this is suitable for a 50mm half-system, as it's a lot cheaper than a FIM chip, I may give it a go.
http://cgi.ebay.co.uk/Ducati-748R-Pe...3A1%7C294%3A50 Any thoughts?