With a few key-strokes on the ol' vintage Rockwell...
...some finely gridded graph-paper...
...& a can of spray-glue
Had ourself a niffty new steel-underframe making jig !
The previous underframe jig, made for the Gilpin Tram caboose model, worked really well.
This one had a slight 'upgrade', with the fine pitched graph-paper, glued to the thick mounting board.
Much easier to mark out & cut the holes for the Plastruct beams to fit into.
Later cross pieces will be easier to locate as well.
Woodie - I think it is the special weathering process known as "found at the back of an old shed, why not put it on Fleabay".
Si : to answer your question, I have searched through my workshop drawers as far as I am currently physically able, but I cannot find my brake shoe box. I remember the suppliers address was Harrow UK but I cannot find any such on t'internet. Maybe the old Harrow Model Shop (RIP) ?
I intended checking the dimensions of an O gauge shoe but all my O wagons & stuff are packed away in crates currently out of reach as I am in U.S. On30 this year (supposedly).
From a quick IT search I cannot find any mfg's of solid, not fold up etch, wagon brake shoes; really bad news.