Note that xconq 7.4 is from 2000, so you might be better off building something more recent from CVS instead. Do ask on the mailing list if you can't find what you are looking for. Having said all that, here's where you get 7.4:
UK Mirror Service (this is a very well-done site, especially if you're in Europe)
The following files are available for download.
The README file:
ftp://sources.redhat.com/pub/xconq/README
The NEWS file:
ftp://sources.redhat.com/pub/xconq/NEWS
All sources:
ftp://sources.redhat.com/pub/xconq/xconq-7.4.1.tar.gz
Macintosh binary:
ftp://sources.redhat.com/pub/xconq/xconq-7.4.1.sea.hqx
Older stuff:
ftp://sources.redhat.com/pub/xconq/Old