My first feeble attempt at weathering armor

It does look like you’ve got the dry brushing technique down pretty well, but to know whether or not your efforts here were a success I’d need to know what look you were going for. I’ve seen older obsolete tanks sitting on the edge of a range that had been forgotten about for decades that looked a bit like that. But a lot of modelers seem to forget that by the time WWII ended none of the allied tanks used in the conflict were more than a few years old. In the case of the Pershing tank they were about a year or less and had only been in theater for a few months by wars end. With the exception of some possible battle damage a Pershing would’ve been in near new condition. One thing you might want to try after applying the base color to a military vehicle is to take some of the paint you used as your base and mix it with a small amount of white to lighten it up a bit, then dry brush that lightly over high points. It’s a nice looking effect when done well. As for weathering, it’s very easy to get carried away and go too far. A lighter approach is usually going to produce better results.