Oh, another tip I forgot......
I 'think' the threaded tubes in the cvds are threaded and
then cross drilled for the pins. In a couple of mine there were bits swarf left from drilling the holes. This might have been why your grub screw didn't nip up.
So, before you clean everything REALLY well, run an M3 tap, or a screw, or even a screw with a slot ground in it right the way through the threaded tube to clean out any manufacturing swarf.
G