> I just noticed on one of my computers that the following have disappeared
> from the upper right section of Gmail (to the immediate left of the wrench),
On my web browser (Chrome), the only thing to the immediate left of
the wrench, is the box with the URL. I'm pretty sure that entire line
"belongs" to Chrome (i.e., your web browser), not to Gmail; so they
are not part of Gmail, and won't show up except on those computers
with web browsers where those features are enabled or installed.
Perhaps you never installed them on that particular computer.