Create Customised Ribbon in Excel 365

I have an Excel workbook which was built in Excel 2010. It has a customised ribbon which drives certain macros in the worbook. My client has recently upgraded from Excel 2010 to Office 365. He can no longer see the customised ribbon (XML) for some reason (even though I have tested it on a version of 365 outside of his network and I can see it). Instead of trying to work out why he can no longer see my customised ribbon, I prefer to simply rebuild the ribbon not in the XML style which I currently have, but using the built-in ribbon customisation functionality of Excel as described in this article: [login to view URL] The new customisable ribbon must resemble as close as possible the existing ribbon (but I appreciate that the icons used are not part of the Microsoft suite so happy to accept substitutes). Attached is a screenshot of the ribbon in its current XML format. The actual workbook will be provided to the successful bidder.