At last I got around to replacing the panel in the basement. Although
the old one (Cutler-Hammer CH about 30 years old) still had one breaker
space available, there was just no room to work in it and I needed still
more spaces. Moreover, many of the holes in the bus bar had two or more
wires, which I understand is not good.

This panel had only branch-circuit breakers, the "Main Switch" (tied
100A breakers) being in a panel in the garage (back-to-back with the
meter), with that panel containing just one other breaker feeding the
garage lights and outlets.

The first thing I noticed was that when I switched off that "Main
Switch" in the garage, the garage circuits were still live; IOW, the
breaker for the garage circuits were connected directly to the meter. So
the "Main Switch" is not really a *Main* switch.

When I started ripping out the wires (previously labeled) from the panel
in the basement, I discovered things I had not noticed before because it
was just too crowded to see or because I had never checked:

(a) The box bonding screw was not screwed down, so was the box even
grounded properly?

(b) The ground conductor from the panel in the garage was not connected
to anything: it was just folded back on itself and stuffed into a
corner, hidden by branch-circuit wiring. (The branch circuits
nevertheless had grounds, because their neutrals and their grounds were
both connected to the one bus bar that was connected to the neutral
conductor from the panel in the garage.)

Was this kosher at the time it was done (30+ years ago)? My
understanding is that now the "Main Switch" in the garage would be
considered the "Service Disconnect", the main breaker in the new panel I
have installed would be the "Main", and there should be separate ground
and neutral buses in the panel in the basement (now technically a
sub-panel). Have I got this werong?

The new panel (32-space 200A CH) has separate neutral and ground buses.
I connected the neutral from the panel in the garage to the neutral bus
and the ground to the ground bus, but did not connect them together in
this panel. Is this correct?

Perce