Replacing Vent Seals

I have a Series III 88', 1976. Decided to replace the bulkhead vent seals recently because they were starting to fall off by themselves.

I got myself a pair of MUC4299 from Paddock, which are flagged as suitable for Series 3. Problem is, they don't fit anywhere near the space the old seals did. They leave quite a gap around the sides that's just asking for water to seep in. I would be gluing them in, but still..

Does anyone have any advice about fitting the buggers, or any place I could get seals that are the right size and fit properly without looking like a botch job?

Thanks!!

just fitted these myself on my 109 series 3...got the same as you but do not use glue as it did not work on mine....take the vents off by removing dowel pins and the 2 x 8mm nuts etc....use wd on the linkages and work it in as its easier to put the vent back on if you can move it fully up.....clean up the area and i used sikaflex to glue the seal in....then when dry i smeared it around the inside lip and also around the outside of the seal and cleaned excess of with spirit wipe....its harder to close the vents as the new rubber is thicker but i havent had any leaks whatsover