This example shows a tyre width of 3.5 mm for Gauge 0 Fine.
For other standards remove more or less metal from the back of the wheel to give your chosen tyre width.
3′ 7.3″ (1100 mm) diam., 10 oval spokes; rectangular inner rim, apparent tread 3.45″, tyre width 145 mm.
Hub 15″ face dia, level with the tyre.
Sources: works drawing.
Casting: 24.4 tread dia., 21.0 i/d, hub level with the tyre.
Casting prices and stock . Netherlands, loco sets, price list
Scan of a casting in a set for a Netherlands SS 700/NS 3700 class 4-6-0, 8 wheel tender
7 Sep 2017