Any Devcon, Loctite, or JB Weld epoxy should be more than strong enough for "gluing" pearl inlays into piston buttons. I have used all three brands and got them from Lowe's.
I used the blue-top Loctite superglue to glue my own 'custom' valve tops onto the valve buttons on one of my tubas. Did this about a year ago and they are still perfectly intact.
Don't get this stuff on your fingers though.....it sticks within
seconds. Learned that the hard way

It also makes my eyes water and literally heats up whatever it is put on while it is bonding the parts together. This stuff is strong!
I like the JB Weld and Devcon stuff too, depending on what I am using it for. I have no shame using them on my old tubas

For store brands, JB Weld has the strongest psi's. and highest temp. tolerance. But I like the Devcon epoxy for it's ease of use and that (to me) tend to be less 'brittle' than the JB Weld stuff, even though it's supposedly not as 'strong'.
Devcon gel epoxy:
^
This stuff dries a creamy-clear color, good up to 200 degrees F, and 2500 psi. Just go to your local hardware stores and check out the epoxies and read their descriptions. See which ones have the color (when mixed & dry), heat/temp. tolerance and psi strength you want.