A quick question I hope soneone can answer. According to my Norman Spink drawings the smoke box tube is 14swg brass, but modelworks used a machined 6mm steel tube. Can any one expalin why the big difference and why so thick. Clearly brass is expensive but is steel the right way to go.
I don't have a Britannia but on my Modelworks/Winson 9F the smoke box is aluminium so the extra thickness is needed for strength. On my Winson 7 1/4 Baldwin it's steel but definitely not 6mm thick, more like 3mm. If yours is steel it sounds unnecessarily thick.