So, I, like so many other's in Canada, have a lot of time on my hands. My 2003 Discovery had an obvious water leak from the the sunroofs. and of course, the head liner was detaching from the roof shell. A friend of mine is a service manager at an import dealership and was able to print off the instructions to remove the head liner. I'm glad that I had that reference material. I'll get back to the head liner later. The drain tube connecters were not broken, and only one of the drain tubes was blocked. I removed the drain pans to find not only a lot of debris in the pans but also, each of the four drain inlets ( the plastic tube connector bits that are "glued" to the metal pans ) had glue compound that was either poorly applied, or had shrunk on each side of the cup. I used a thick black gasket compound to fill the the gaps. Now that I see how these trays work, I can only wonder why LR did not add drain tubes on all four corners of the pans. I live in a hilly, rainy part of Vancouver Island. I'm now going to make sure that I park on level ground, or if there is a slope, front facing down hill!
I've stripped off the roof liner fabric and remaining foam and glue. I've placed the clean roof shell in the warm sun just to ensure that any remaining moisture is dried before I apply the new head liner. I'll be happy to hear about the process for positive results that anyone has had in applying new head liner material to the shell. I've worked with applying Arborite to wood surfaces but the process of applying two glued surfaces to a bowl is something to really think about...
I hope that the little bit of information I shared will help someone some day. Cheers. Stay safe.

 

Mines looking saggy as well the previous owner stapled the head lining up with massive staples, I’m thinking I’ll have to fill the holes and then paint , might get a quote from a upholstery shop if I go the glue material way, and work out what looks better

 

Shell on the work surface

Rear

Full

I'm pretty happy with the result. I hope that this might help you decide. Check out my post from today for some tips.

pz