I've managed to put a Bachmann Manor body on a Hornby Grange chassis. A lot of filing and cutting involved. You need to reduce the length of the chassis at the back and reshape it at the front. Also, the edges of the firebox need to be filed to get the motor into the body - a bit of a "trial and error" job. The motor spindle fouls the firebox backhead, but I also wanted a "glowing firebox" LED and there is insufficient room to do this, so I hacked off the firebox backhead and used a plastic one