<VV> Backlight (rear windshield) advice request - for LM coupe

[Andy Kinzelman]

To All,My friend has a LM coupe - where we assume the backlight is completely loose from the gasket/seal material; as it rattles around.  Later this year he intends to replace the glass with a proper fix; but can't do so before this weekend (big show).

Can anybody suggest a temporary repair with the trim and glass removed?  I thought of either a 1/4" bead of black silicone caulk, or possibly a bead of slow setting gel superglue on top of the existing seal material to hold the glass in place; then replacing the trim.
I know these are both half-assed repair options, but this will allow him to use his car for the balance of the season.Thanks,Andy K.Wisconsin