Hi all
My mk1 (74 1300) has 2 rectangular rubber grommits prob 30mm x 10mm with slots in them sitting outside from the window seal on each side of the car.
Proper grannie 1 owner car not modified, I havnt seen this before is it for opening rear quarters? or some kind of sunshade mount?????

From memory they are on the vertical, between window and door and where for opening 1/4 window hindge, which was flat stainless or chrome with a couple of bends that where pushed through the slots in the rubber.

Yes, opening rear quarters. My Mk1 has/had them too but I'll being putting solids back in. The mounts on the B pillar were as hendo described and glued to the glass. The pop out hinge mechanism then bolted to the little flat on the inside of the C pillar and again was glued to the glass. I still have all the bits somewhere so I can take some photos if you like.

Found out after a bit of searching the windows could fall out sometimes on rough roads so lots were changed for solid rubbers, thanks for the pic offer simon its ok though mate i ts just another job for the mig