Pablo, there is another way to look at your head gasket material problem. Considering Chinese engine tolerances, an extra 0.004 inch of gasket thickness would have relatively no effect.
Have you calculated how much it would reduce the compression ratio and thought about whether it matters or not?
as another poster said, aluminum producers tend to deliver on the small side of the spec. They make more money that way.
A typical thickness spec is 0.032 +/- 0.0025. More often that not, the actual delivered product I have seen was in the lower 1/2 of the spec. Material that was thinner than spec was rare, maybe because the supplier knew they would get the opportunity pick it up at their expense. They must have sent the stuff they knew we wouldn't accept to the place Tempest worked at.