I've just found that there are now (June 2015) 32-bit and 64-bit RPMS for
Fedora 22 here, as well as rpms for earlier versions of fedora:
http://download.opensuse.org/repositories/home:/zhonghuaren/Fedora_22/
e.g.
ctwm-3.8.2-4.1.x86_64.rpm
ctwm-debuginfo-3.8.2-4.1.x86_64.rpm
Is it worth adding a link to that site here?
http://www.ctwm.org
So I've copied and installed the 64 bit versions on my desktop PC and laptop.
(I have not yet found out what the second one does, and have not installed it.)
Aaron