A search on the web and Land Rover forums revealed a lot of frustration over vent seals, and no real answers. The seals themselves, like almost everything else on the aftermarket side of things, come with no instructions. The most common answer that I found was to keep the vent pressure on the seals by clamping or whatever, and after a few weeks or months the vents should be properly seated. This can't be right. When original Land Rover owners needed new seals, did they just have to endure rain and snow and blowing wind in the cabin for weeks until the vents sealed properly? I can't see a practical and experienced engineering company like Land Rover doing that.
It seems logical, at least to me, that the original and correct seals must have had grooves of some sort, and not have been as thick.
I tried cutting a slit in the seal for the lid edge by tracing around the vent lid, but that wasn't successful as the lid lip didn't always catch the slit.
Peter at 3 Bros. kindly sent photos of the aftermarket seals they sell, and they appeared to have the same flat-top profiles as the official current Land Rover ones. The only seals I could find on the web which appear to have some sort of shape that might be correct are part number MUC4299, as imaged on the L.R.Series website here. I'll have to look into this, preferably with Peter, even though they are apparently only for Series 3 and Defenders.
And so, I experimented with other seal types, and one which appears to work well, at least in the short term, is a self-adhering, water-proof, closed cell outdoor rubber weatherstripping available at Home Depot here. I bought a few sizes to try things out with, and this was best. For now, I think this will do.
(If you know of any other solution, leave a comment!)
Here, view of the weatherstripping. Pro's and con's: Pro: very inexpensive, easily available, and easy to remove/replace if necessary. Plus, the lid can be lowered/closed completely right away, with fair pressure on the seal. Likely good for keeping wind and light rain out, and heat in. Con: May not be good for heavy rain or trying to chip ice off of, and, don't know how long they'll last.
A view with the lid closed. (Incidentally, the weld blobs around the hinge welds, etc. are factory original, and so I sort of like them, which is why they're still there.)
On a different note, and no big deal other than it's really starting to feel like a Land Rover now, the windscreen went on today. (By the way, the high-quality Land Rover-manufactured bulkhead-to-windscreen seal, also appears to be too thick, as with with the vent seals. Even with considerable force the windscreen won't lay back at completely the correct angle. May just go back to the original 51 year old seal, as it was working just fine except for being slightly tattered at the ends.)
