300E leaks (looking to get a DRY w124)

About 18 months ago, we purchased a 1987 w124 300E for my wife to drive....
Well, I have been using it most of the time. :-)
Last summer we were driving north, and a nice summer squall hit us, and it was pouring. About 10 minutes later, it started raining inside as well. It was so bad, that I had to stop and get a towel. After the experience, I took it to a body shop friend of mine, where they proceeded to blow out the 4 corners of the sunroof drains.
2 weeks later, on another squall..... Pouring again. Desperate, I took the front sun visors off, and the front sunvisor cover, and I saw that the drains were badly rusted. I took out my handy Dremel, and proceeded to clean up all the rust, and then to repaint, and finally seal the pipe with some silicone, and most importantly... a zip tie.
MB never put in the zip ties there, and what happens is that humidity and moisture get trapped, and rust the outside of the drain, creating a way for the water to come back at you. After fixing this. the front never ever leaked again, and my floors are mostly nice and dry, except for me getting in and out.
Last week, we noticed a very troubling development, and we saw that the rear carpets were wet. The rear, is not nearly as easy as the front.
So, today, being in MA, winter and all, and the temperature is above freezing, I decided to risk it.
I started by taking the seats out, finding that the vacuum pump for the doors was missing altogether.... No wonder why they did not work! hmmmm. this might not be a new development! The pump happens to live in the same spot that was flooding. After removing both c pillar panels, I took down the rear part of the headliner. That was quite a chore. It has a nice build but it took a bit to figure it out.
Once the headliner was down, I could clearly see that the downspout was wet, but not too rusted. I took the rubber drains off, and with some pressurized air I cleared them, and proceeded to sand, primer and paint the spouts. I waited until the spouts were nice and dry, and applied some silicone on them, and then reconnected the downspout hoses, and tied them with zip ties. Hopefully this will last as long as the car has so far, or 23 years. :-)
So, if you have a very humid w124, and can't figure out where the *&*(^^ the water is coming in, check the downspouts! If they are rusting, or even with old age the rubber is not as supple as it used to be, and water will find a way back into the car.