It sounded like the Blacksmith thought the meshing problem occurred further up in the drive train. May have interpreted his description incorrectly. I have only heard of the muff gear being too narrow and not meshing correctly. I guess if the idler gear is also too narrow that will not help the skinny muff. I have to place an order with NWSL for some wheels so will grab one of their muffs also. I have heard that they actually made the gear wider which should help things. I am sure if the muff splits this is also a big problem. I have some bowser mechs where this same thing has occurred. The wheels don't stay fitted anymore big problem. Time to make some of these gears also.
Hopefully with the NWSL version in hand I can get up to Moss Vale and cut a few gears. My mate is biting at the bit to get stuck into it. He loves showing us young fellas how to machine things up.
I have never seen flat spots on a model locomotive wheel before that have occurred during use! Interesting.
Yes I agree that is also how I interpreted what Geoff said. I was only wondering if the muff already deliberately designed to be offset, could slide further over one stub axle and to maintain gauge have the other stub inserted a shorter distance thus allowing the internal gear to be further out of alignment. Unfortunately I am not in a position to pull the engine apart and check just now.