Thanks!
I'm looking at ISIS BBs online, and they all show a lock-ring or flange:
On the right-hand side in this pic:
My bike doesn't appear to have a lockring/flange, on either side. the drive-side look the same as the pic I posted above.
Also, are there any "good" replacements you'd recommend? "Good" meaning "better or lighter than stock".
My drive-side: