There aren't many plans available for an Auckland A Class Dinghy, and the one that survives depicting the coach work doesn't actually match the chassis of Car 26 at all. This being the case, in preparation for the writing of the Heritage, Preservation and Restoration/Re-Construction plan for car 26, we have surveyed, measured and documented the Tram's chassis. The result being a 3D CAD model.
Interestingly enough, despite all our research and wading through archives, microfilms and hundreds of documents and drawings, the chassis of 26 didn't actually fit on the truck we re-engineered. The truck was an inch too wide! By sheer luck we found that a few frames of the microfilm hadn't been scanned, and there it was, hiding at the start of the reel, drawing Z4 'Axle for Single Truck'. We substituted the new axle drawing in the design, and miraculously everything lined up.