The way I see it, there are two main points of view regarding the Mk VII bags...
The antiquarian outlook; the bags are 60 years old, they're part of our history, heritage and whatnot. That's the
"This belongs in a museum!" standpoint. The bags should be treasured and not meddled with. Too much, anyway - it's OK to remove original webbing strap and replace with leather ditto, but the buck stops there.
The pragmatic outlook; the bags are purchased, not to add to a WWII collection, but to become Indygear. Bags do not come screen-accurate from vendor. Individual purchasing the bag must make alterations in order to turn bag into Indygear. Individuals have, well, individual perceptions on what to do with bag to capture the essence of Indygear.
Do I endorse either of the above standpoints? Yes, both. I have worked in a museum, taking tender care of centuries-old stuff. I do possess a slight antiquarian POW, and have rather orthodox views on certain preservation issues. On the other hand, I own a Mk VII with a stripe and, occasionally, it bugs me. I've been nourishing thoughts about dipping the wretched piece of fabric into a bucket of bleach. I've thought about dyeing it... sure it's made in 1943, but alas, that's not important in this context. There were hundreds of thousands of those bags made, well enough to flood every museum with gas mask bags. There are post-war bags, lots of them, too... what we do, fellow gearheads, is rejuvenating these bags and actually giving them a renewed value... cherishing them in an Indy fandom context. What we choose to do with our personal belongings is up to each and everyone of us. I have the highest respect for QuantumGirl's and G-man's desire to get rid of that blasted stripe, as I have equal respect for IndianaMikey's view on immersing a Mk VII in various chemicals. (Besides, as for IM's negative attitude, at least I spotted the "wink"

emoticon at the end of his last post... it wasn't mean't to be a bashing, if I understood things correctly.
Just my thoughts. Not my intention to step on anyone's toes.
/SJ