4′ 4″ diam., 13 oval spokes, inner rim with a distinct ridge. Apparent tread 5¼″, tyre width 5½″.
Hub 13″ face dia., level with the tyre.

Source: borrowed works drawing. Also Johnson, Locomotives of the Great Central Railway, vol. 2, p. 154.

Casting: 41.3 mm tread diam. 33.5 mm i/d. Hub level with tyre.
Tyre width for scale modellers: 4.4 mm.

Casting prices and stock . GC loco sets, price list

Scan of a casting in a set for a GC 2-8-0 8K . GC 4-6-0 9P