Thanks for the reply.
Late last night I got brave and tried it. It worked perfectly. There were a number of other things I didn't understand from the 'Conquest on Linux' document. I've always run on Windows boxes before. But given enough time and coffee I finally tumbled to the fact that there need to be two dgate instances, one running as a standard daemon, and one running from cgi-bin, each with its own (appropriate) dicom.ini and copy of dicom.sql. I did not get that at first.
Some of us are slowing with age.
-- Dave