I've been at this for over 25 years and I still learn new things about marbles nearly every day. It's one of my favorite parts of the hobby. If you stick with it, things will eventually start falling in place. Now that you've seen what Vitro Conquerors look like - the top patches can be many different colors, but beyond that they are very similar, having white glass veneered over the rest of the transparent base glass, or sometimes appearing more like internal filaments - you can probably look at the rest of your marbles and find more of them. As I said earlier, they are one of the most common vintage marbles out there.