flytire, that's really cool! I can honestly say I've never seen that before.
How can you be sure that the seed bead is smooth enough on the inside, not to cause the same problem that you're attempting to repair? I've seen plenty of beads that were cracked or deformed. Is there a certain quality you would need?
Not arguing with the repair, just asking!
The Griffin ceramic bobbins have what I'm assuming (yes, I know!
) are inserts of much higher quality than a seed bead. I was thinking more in terms of expanding the old tube & adding the ceramic insert, although as you've shown, I would think a ceramic insert with the shrink tubing would work fine if you could get the inserts.
I have several old bobbins in need of repairs!