4′ 1½″ diam., 12 rectangular spokes, rectangular inner rim, apparent tread 4″.
Hub 12″ face dia., level with the tyre.

Source: works drg in Russell, 1: 179.

Casting: 39.3 mm tread dia., 32.5 mm i/d., hub level with the tyre.

Casting prices and stock . GWR loco sets, price list

Scan of a casting in a set for a GWR 0-6-0 Dean Goods