Hi Tom
Not sure it's an actual font, more likely the standard mould letters they had in the workshop since the 1900s. There's a bit of everything in there, from a typographical viewpoint. That flat-topped 3 is the toughest to match.
If I was to tackle this, I'd take a standard font, drop the alphabet and numerals into a graphics package, convert it to outlines and edit to make things look about right. Then I'd assemble everything from that. I might consider playing with this later, if you can wait a while.