....right, I have now sorted out the cab windows. The windows are a sandwich of an outer round frame and an inner bigger frame around a disc of clear plastic. A fellow modeller has a 10 mm punch and has offered to lend it me to punch out plastic window discs, so more of that later. I would advise that the outer round frames have the cusps filed off and the window apertures in the cab front and rear should be dressed with a half round file so that the frame sits nicely inside it. Maybe this is best done before the cab is assembled. The plain outer frame sits within the aperture when finally fitted up, the window assemblies are pushed into place from the inside of the cab. The inner frame (sits on cab inner) has a small square of brass fitted to it to represent the open position bracket, and thin wire to represent the chain that holds a pin to lock the window open on the bracket. A similar bracket has been made for the underside of the cab roof which locates the window in the fully opened horizontal position, NER round cab windows are hinged at the top.
The etch includes a guard bar ring with half etched holes showing drilling locations. The holes were drilled out 0.4 mm (drilling and addition of bars was done whilst the part was still in the etch for ease of handling,) and the bars (44 for 4 frames!) were cut and bent from 0.376 mm rod. I thought this would be a nightmare, but once I got my eye in it was quick and easy, and quite therapeutic. A suitable width of 0.5 mm thick sheet was slipped between the bars and the ring, and the bars soldered in place on the rear. Soldering one end first allows a bit of spacing adjustment with some tweezers and then the other ends of the bars were soldered up.
The trickiest bit was actually soldering the finished bar assembly to the cab. It has to be centered on the aperture with the bars vertical. I used Blutac to hold it while checking.
Hopefully some smokebox progress next....