Thanks Gents,
I have a roll of the Black butyl tape that Colin mentioned, but cannot work out how to use it, as it is terribly sticky and will grab onto anything it come in contact with.
I'll certainly try the Kerosene, as I have plenty of that around. its oily and a good solvent as well.

Thanks for the tip on placing a section of rubber between there glass edge and the frame.

My current thinking leans towards cutting off one side of the U Chanel I have, to create an L shaped rubber section. Then applying this to the edge and one Side of the glass, and possibly (but not necessarily) using the butyl tape to hold the L rubber seal in place. Using the 1.5mm space that should now be created, sliding the glass and one sided seal into the frame. Finally, using windscreen sealer (caulking) to fill the inner side gap between the glass and frame to ensure that the glass can never move.

Any thoughts, comments or advisories on that approach?

regards
Jeff