The LMR moisture barriers are definitely thicker than the originals.
I took a look at all the ones i have, which i'm glad i did, it sorta gives a map of what holes need to be kept during the kilmat install.
It also doesn't look like they get taped or stuck on to the door, more like there are push pin holes and they get mounted to the door panel instead.
I cut up 3 mil contractor bags to make door moisture barriers. Stuck on with butyl window weld. That stuff stays sticky. Works great. I buy them for the garage trash can.
I finished up my passenger side door yesterday. Behind the speaker an entire sheet of kilmat fit, so i just used a full sheet there and then surround the speaker inside the door as well as possible. Then i just used random strips on the door support and panel inside. Then the door itself, i install the kilmat on all the parts i though the panel could rattle up against the door itself. Nothing real special, i don't really see what covering the entire door would do.
I also decided to put the moisture barrier back on my Pside door. Honestly it was too easy not to. It doesn't really get mounted to the door panel, it get glued to the door itself.
At $23 a set i'm not sure i'd be making them myself. They are pretty solid and i can't see them tearing period, even if you had to pull it off.
The fit was pretty much perfect. Are they really necessary? Not sure, but it was really little to no hassle like flimsy originals, these keep their shape.
Edit: One thing i will add is that i bet the LMR moisture barrier helps prevent road noise from coming through all the large openings in the door since i covers pretty much the entire thing with few openings.
From the factory, the vapor barrier is actually affixed to the door, not the door panel, with ribbon sealer. Don't know Ford's exact stuff, but here's the 3M product I got...
I cut up 3 mil contractor bags to make door moisture barriers. Stuck on with butyl window weld. That stuff stays sticky. Works great. I buy them for the garage trash can.
My '85 had the plastic barriers, but they are thin and not near as durable as the R.E.M. brand vapor barriers that I got at NPD. The ones at LMR may very well be the same part as the NPD ones, just sold under their 5.0Resto brand name.
Buy part #M-20126-1BK Watershields, Door Trim, Plastic Style, (2) Incl Rh And Lh Side, Designed To Seal Out Moisture And Protect Door Panels, Adhere With 3m8509 Compound for your classic 1981-1986 Mustang from National Parts Depot. Free shipping on orders over $300, fast delivery & everyday low...