Does this malleable iron hub have the Mason and Burns Ltd logo on it perchance - M&B ?
Mason and Burns did a fairly large amount of business supplying malleable iron castings
to the motorcycle trade, from pre WW1 through to the 1980s.
Malleable iron being a form of heat treated cast iron.
But seem to be a fairly obscure entity, with little in the way of info - or pics - on them
They were in Pleck Rd Walsall for many a year, in amongst a large number of ironfounders and foundries..
In amongst this bunch - somewhere.
Thats Walsall Hospital in the upper half. Walsall Canal towards the bottom.