Born in Chicago and lived across from Midway Airport. Grew up mostly in Oak Lawn. Moved to California and 5 years ago to Arizona. Chicago had the best food. Pizza in California and Arizona sucks for the most part. My favorite hobby shop was called "Trost Hobby Shop " and if my memory serves it was on 63 rd. st. Any chance it is sitll there ?
Maybe since it is removable ( if it really is ) it could be used as a masking material. (?) It's a rubber product and I myself wouldn't bother with it unless someone uses it with good results that they can post.
Doing the wash is simple. Just dilute some black waterbased paint and flow it on. It will sink to the lower portion and you can just wipe the front if needs be.
Very good job. I like it. I would suggest only that you might want to try a black wash to the grill area to add depth. i think you would like the results.