I know this is an old thread, but I believe I have found a repair cure for these peeling Medicom Darth Vader suits:
Remove all remaining pleather from the suit. Rubbing with the thumb, or using duct tape will do it. Time consuming, but it must be done.
Next, make sure the remaining cloth suit is free of any debris.
Then spray the suit with:
Mighty Sealer, a black colored, spray liquid sealer, that goes on wet (like paint), seeping into the fabric, then when it dries, it turns into a flexible, rubberized coating.
I bought this stuff today @ Big Lots for $8.95 (Bed Bath & Beyond has a similar product for $12.99, and there is also a TV infomercial selling a similar product for $19.99), for a 15 oz. spray can, so as to seal a leak in the edging of a sky light.
After I was done, I looked at my peeling Medicom Vader costume, and wondered if it might help it. I took the costume off the figure, removed the remaining pleather, and sprayed the costume! I figured, what did I have to loose, the costume was bad anyways! It takes about 30 minutes to dry. After it dried, I shot it a second time, and this time let it dry for 5 hours. I wanted to make sure it completely cured before I touched it.
Once it was cured, I was presented with a slightly stiffer, but completely flexible costume, which actually, more realistically represented Darth Vader's body suit, than in its original, pleather covered state!
The body suit dried to a rubberized, satin sheen finish, which more accurately represents the leather look than the pleather did. Since the rubber is flexible, the figure still has the same movement as before, but not with the same stress on the outer coating.
Also, since the cloth suit is now rubberized, the gloves actually stay on better!
This stuff sprays out thick, so I would suggest spraying it in two light coats. I inadvertently sprayed mine just a little too heavy, so that once it dried, I had lost some of the ribbing stich pattern in the suit. This was easily remedied, by lightly re-etching the lines in the dried coating.
Overall, I am very pleased with the look this sealer produced! Now I no longer have to look at the Vader figure on my shelf, and be upset that I spent $200.00 on such poor quality control by Medicom.
I hope this helps!