This is my first project on hackaday.io and I've already added a log item to the details section! Apologies... Will continue here!
Having cut the main sections of the TTTTT on the CNC router I checked fit and glued them up. The first couple of panels required a little light dressing of the tabs as they were too tight having cut them with no tolerance/clearance. I adjusted the toolpaths so that I did a minus 0.2mm cut on subsequent parts which made them fit. It would be better if CNC routing to separate the paths so that just the tab sections are cut undersize rather than the contour of the whole part, but its definitely good enough for this project!