I finally got my arm behind things and I do have a water pressure
regulator. Is there a typical pressure this is set for?

I would try to call someone in county government, or search their
webpages, but my first try failed, and I expect success will take
forever.

I live in a northwest suburb of Baltimore, and I seem to have plenty
of pressure, or the standard amount of pressure. We have 3 big
reservoirs that supply water, one of them 5 miles up the road from me.
The toilet closest to the water entry point does a complete cycle in
32 seconds, from pushing the flush level to the tank being refilled.
(I figure about 6 seconds of that before the flapper shuts, so 26
seconds to fill the tank.) Thanks.