The GWR 43xx 2-6-0s had the same wheelbase, cylinders and motion as the large Prairie Tanks (41xx, 51xx, 61xx, 81xx) so having picked up a Mainline 53xx body and tender and a redundant old Airfix GMR 61xx Prairie Tank, I investigated if the Mogul body would fit on the 61xx chassis.

I measured the width of the Airfix motor and found it should just fit into the body.

The chassis was disassembled so that the chassis block could be modified. The Airfix chassis block incorporates large weight blocks which fit inside the 61xx tanks. These were removed in a few minutes with my old angle grinder/cutter. The bunker end of the chassis was shortened so it would fit under the cab / dragbox (a plastic body locating protusion has to be removed from under the 43xx cab) and the lip on top of the chassis ahead of the cylinder locating slot was removed. The photos show the original and cut down chassis block.

The chassis was reassembled with the cylinder block fixed in position using an 8BA bolt, washers and nut using the original chassis fixing hole already in the chassis block.

The loco is rather light in weight at the moment and I intend to add some lead in the boiler once I've settled on a place for a decoder.

Note: 1 The first Airfix Prairies had unflanged centre driving wheels but the later Airfix GMR and Mainline versions were flanged.Mine was an Airfix GMR type.

Note: 2 The Hornby 61xx Prairie has a different chassis block and the motor lies sideways so probably wouldn't fit inside the Mainline body

The Airfix chassis block