Squelch the Squeek

[Whoops]

Whoops i'm probably wrong but looking at your second picture with the underside of the calipers it seems that there are wearmarks on one surface  ( the left part ) of the caliper.
The right hand one seems a bit recessed in such a way that that pad may not be supported?

https://cb1100forum.net/forum/attachment.php?aid=192



Not sure if there is enough space to put some of that shim on those load bearing surfaces and see if there is a difference.

Just one of those wild ideas that emerge from my subconscious mind.

I saw those areas where it appears it was making contact. I did apply some grease there, but the shims are used up so hopefully grease will make due.