Well now the railings have been revisited. I am now using a brand new 0.71mm 60/40 solder and a Rosin soldering flux paste to see if the previous result can be improved. The styrene solution for the rails is an option of last resort for me.
The reason why I am persisting with this is because I really do need to sharpen my soldering skills as I contemplate the Dandry Mire Viaduct safety railing and kit building the semaphore signals and the Network Rail radio link tower, not to mention the layout track droppers and so forth. Also I reason copper wire may be more forgiving should ‘the hand of god’ fumble near the mainline. In a perfect world there be no derailments!
Perseverance pays!! As the picture shows the safety rails whilst not perfect, are to my own satisfaction and hopefully reflect the prototype Ø 42mm pipe work.