With the exception of some minor tweakable changes, Trinity desktop is closer to KDE 3.5 than MATE is to Gnome 2.32. Here's how to install Trinity on Fedora:
sudo yum install wget
Now for the version specific part.
Now, I didn't like the way the Trinity team had made the desktop icons, so I made the default KDE 3.5 stuff: Home, System, Trash.
I've also noticed that there were some issues with the icons. Either they were gone or transparent on some.
All in all, Trinity is very nice. Just a fair warning: Don't install KDE 4 with Trinity...things get weird. (i.e. two programs called 'Konqueror'.) Quite confusing to say the least.
Have fun with KDE 3...sorry, Trinity!