What bugs me about this is that every idiot with a can of spray paint is going to think they can just grab some white paint at the hardware store and a Kirk mask and create Michael Myers the "Tommy Lee Wallace way." Spray paint today is not the same spray paint made in the 70s. Spray paint in the 70s was lower quality, didn't coat as solidly, and rubbed away easily. That's why there was so much exposed Kirk flesh tones on the mask by the end of production. The paint just rubbed away. Spray paint today is usually acrylic based, coats more evenly, and doesn't rub away as easily. It's the acrylic that causes the paint to crack. That's why most mask repainters today use air brushes and mix liquid latex into their paint. The liquid latex makes the paint mask friendly. I got into an argument with a guy over Facebook about this. Two years previously I told him don't just spray paint his mask, it'll crack. He did it, and then argued with me about it two years later and said it looked totally fine. When he showed me a picture of this "totally fine" mask, it looked like somebody had taken a hammer to a window.
I'd say be careful of buying any "converted" Michael Myers masks on eBay for a while. They may not be painted to last.