It has been a while since I did any work on the roundhouse roof so I recently added the smoke hood support wires, 4 to each hood, to the 22 that are inside the shed.
The roof is entirely scratchbuilt from brass section and nickel silver wire.
The smoke hoods are of two types - 3 older wooden types which are ex Midland/LMS in origin which I scratchbuilt from plasticard and brass angle, and 19 'asbestos/concrete' units which are cast in resin by my Friend Morgan from a 3D printed master. Morgan also produced the etched supports on the lower edge of the units.
I have used Markits WD handrail knobs - 4 per unit - as hood anchor points for the nickel silver wire supports.
Once finished I sprayed the complete roof with Halfords grey primer.