Pat Hammond doesn't mention which model the tender came from in Vol 3 of The Story of Rovex other than it was an existing 14ft wheelbase chassis. It was notable in being the first steam loco model to have glazed cab windows but those hardly mitigated its short comings. Pat noting the front bogie wheel was 2mm too small and a spoke too many, the driving wheels were not accurately spaced and had three spokes too many, loco body too long, cylinders too deep, no daylight under boiler, front bogies set back too far, tender c 2ft too long, and a chimney unlike the prototype.