Hi Michael
The wheels should be quartered as it's known i.e the crankpins on one side should be at 90 degrees to the crankpins on the other for a two cylinder engine. Which side leads depends on the prototype you are following. I think the LNER used right hand side leading, as did most but there are exceptions. so do check I'm sure someone on the forum will know for a B1.
The good news is you can't see both sides of the engine at once so no one will probably ever notice!
Dave
To make ot clearer looking at the engine from the right hand side with the chimney on the right, the right hand crankpin would be at the three o clock position with rhe RH cylinder at full forward stroke. The left hand crankpin would be at the twelve o clock position and the LH piston mid stroke.
Edited By Dave Wootton on 25/01/2022 14:09:44
Edited By Dave Wootton on 25/01/2022 14:15:45