I found these in an old prototype box they was for a small radio unit project that
never went into production.
They are solid Aluminum with a set screw and was modelled on some 1960/70's kit
6mm standard hole .
If these sell I might run some more, very very nice anodized
size 29mm wide skirt 15mm height 12.9mm inner recess (cover nuts etc about 4/5mm deep