This example shows a tyre width of 3.5 mm for Gauge 0 Fine.
For Scale7 remove more metal from the back of the wheel to give a tyre thickness of 3.2 mm instead of 3.5 mm.
3′ 7″ diam., boxpok welded plate.
Hub level with the tyre.
Source: Winston Churchill measured direct at York, August 1995.
Casting: 25.1 tread dia., 21.0 i/d. Hub level with the tyre.
Casting prices and stock . SR loco sets, price list
Scans of a casting in a set for SR 4-6-2 Bullied Pacifics
27 Mar 2013