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′ 6″ diam., 10 oval spokes, humped inner rim.
Hub 12½″ face dia., 2¼″ out from the hub.
Source: preserved N7 0-6-2T at Cappel in 1995.
Casting: 24.5 mm tread dia., 19.3 i/d, hub 1.3 mm out from the tyre.
Casting prices and stock . GER loco sets, price list
Scan of a casting in a set for a GER 0-6-2T L77/LNER N7/GE
27 Mar 2013