Ian@StEnochs
Western Thunderer
I can think of three options -
1. 4mm scale Austerity locos,
2. 4mm scale CSB pivot points,
3. 7mm scale Sentinel loco handrails.
Personally, I recommend option 3.
PS. Just remembered another use - smokebox handrails on Beyer Peacock built locos from the 1860s onwards.
Andrew Barclay pugs from the late 40’s used ‘Austerity’ style handrail pillars, Cannot call them knobs as they are just round bar drilled for the handrail.
Ian.