Since no one but Len chimed in, either 1) No one else knows or 2) No one cares!
I took Len's advice and reached out to Rick Propas. Rick replied immediately and was very helpful. I am grateful to him for his help.
Here's what he had to say:
"The pencils are relatively easy to fill.
You can either load the magazine with leads and click them through. It will take quite a few clicks to get the lead fed properly into the
mechanism and through it to the nozzle.
Or, more directly you can depress the button and front load the lead through the nozzle."