I copied all my dhcp-host and cname lines from my dnsmasq.conf file to '04-pihole-static-dhcp.conf'.
As part of this process, I corrected the sequence so that the IP address appeared before the hostname as shown here: Man page of DNSMASQ.
I copied all my DHCP (dnsmasq) options to a file that I named '03-pihole-dnsmasq-options.conf'.
Per your recommendation, I performed a "sudo pihole restartdns" and then a "sudo pihole status". That gave me a red mark. I guessed it was one of my options but to make sure, I deleted '03-pihole-dnsmasq-options.conf' from dnsmasq.d and retried "sudo pihole restartdns" and then "sudo pihole status". This time it reported that it was working.
I copied '03-pihole-dnsmasq-options.conf' back into dnsmasq.d and commented out all the option lines except a couple that I thought were totally innocuous. Three or four cycles of uncommenting the options, retrying "sudo pihole restartdns" and then "sudo pihole status" and I had isolated the one offending option line - it was the dhcp-range option which I use to make the entire range static [dhcp-range=192.168.1.0,static].
I now have the dhcp-range commented out and when I restart DNS everything seems to be working fine. I see there is a spot on the UI to establish the range but I don't know where that setting it stored and, more importantly, whether it will accept the static keyword. The idea, and the way I ran it with dhcpd on my old Ubuntu server, is that I only allowed static entries. I would like to do that again with pihole if possible.
And, again, many thanks for the assistance!