Thank you for your eloquent reply. I'm sorry that I neglected to specify that I had, in fact, Read The Fancy Manual. I assure you I would not have asked before doing that first.
That said - here is what I found, and how I ended up adding them back, for any who may be interested:
1) The manual says
Right clicking on any chart in a quilt in the chart-bar and clicking "Hide This Chart" on the pop up menu, removes the chart from the quilt. The chart button in the Status bar changes to . The same thing can be achieved through the right-click menu when clicking on a displayed chart.
To activate the chart again right click this button an then click "Add this chart to quilt"
I believe I mentioned I was using a windows tablet. As such, I had "enable Touchscreen Interface" and "Enable Scaled Graphics interface", well, enabled. The way I hid the charts was long-press, and in the pop up menu, choose "Hide This Chart". However, no amount of gesturing, long pressing, tap, double tab, swiping, or what-have-you would bring up anything that said "Add this chart to quilt". UNTIL:
2) I plugged a mouse in, disabled Touchscreen interface and Scaled Graphics interface. THEN, I found that when I right-clicked on a chart bar button with a red X, it said "show this chart" (unlike what the manual says).
So, I figured it out, and hopefully this will help someone else who has this trouble, and hopefully it will help those who are updating the documentation.
The next time I ask a question, I will be sure to specify that I RTFM first.