Quintus
Western Thunderer
The issue is wider than that - the wheel standards (widths, flange depths, etc), vary within loco ranges. The two Hornby Pecketts have markedly different profiles from one another, they're different again from Bachmann's rough standard, and so on. I think the wagon and coach wheels are generally consistent within product ranges, but since I work in EM, I tend to replace on spec'.
Adam
I had no idea 00 was in such a mess. Perhaps the answer IS to replace all the wheels with those of a consistent standard (I will now duck!)