MXR Talkbox Cap?

from blog Jeff Kaufman's Writing, | ↗ original
I have an MXR M222 talkbox that I'm pretty happy with, but when the tube is disconnected the speaker is very exposed: I'm worried about damage to the speaker, and would like some sort of cap to protect it. When I search for "MXR M222 talkbox cap" or similar I don't find anything. I wonder if it would be possible to make something? Measuring,...