Got word back from the English support over at Thrustmaster Europe:
"Dear Jordan Sampson,
Thank you for contacting Thrustmaster Tech Support
Unfortunately, we have no more microstick parts available.
Thank you
To ensure the most efficient follow-up of your query, please answer directly to this email (do not open a new ticket).
Kind regards,
Your Thrustmaster Customer Support Agent, Nancy
http://support.thrustmaster.com"
Looks like Thrustmaster is truly and completely out of the microsticks now.
With a few other options I’d PM’d Red Dog with, it looks like there is currently no replacement for the microstick.