Tektronix A6302 Current Probe Slide

[mtdoc]

I recently picked up a Tek A6302 on eBay. It is in good shape overall and seems to work just fine.  The only issue is that the small black plastic thumb slide comes off easily if pressure is not applied downward while sliding the probe between open and closed positions.  If you look on eBay for these probes you'll see  plenty for sale with this piece missing or broken.  I'm hoping to avoid that fate.

Any advice on how to best secure this plastic piece to the metal slide it slots into?  I suspect that when new it snapped firmly into place but over time the fit loosened.  It's a bit tricky to glue it without interfering with the sliding action. I already tried with a small amount of cyanoacrylate without success.  The metal slide looks like it may be copper but I'm not certain.