The mate and I got a bit done on the project yesterday but I forgot my phone,so no "on the spot pics"
No worries I will take some pics and post them.
The ended up using a 2.5mm diameter screw because that is what we could find and have the matching tap for same.
The screw was around the same diameter as the original merit screw but metric instead of imperial.
We drilled the connecting arm and found it was made from copper, believe it or not.
There's just the silver solder job to do on the 4mm spigot step joint to the flat sheet that fits between the spectacle parallel bars and
then epoxy the flat into them and Bobs your uncle.
All is good ,then. More pics soon as soon as I complete a few "Honey do" jobs.
Whitesmoke