xfce way back in the day was trying to clone CDE which is open source and actively maintained these days https://sourceforge.net/projects/cdesktopenv/ (really. last release was in november 2025)
Just in case you want an even more vintage experience.
There's also people trying to keep the SGI experience alive, but this one is a clone: https://docs.maxxinteractive.com/
As for as early xfce check out https://xteddy.org/xwinman/screenshots/xfce-default.jpg (I'm actually on that site from 25 years ago: https://xteddy.org/xwinman/screenshots/twm-cjmckenzie.gif)
Instead of Maxx Desktop, check EMWM plus the goodies:
https://fastestcode.org/emwm.html
I won't consider XFCE vintage but sane, boring but working. Vintage would be a vanilla FVWM, or MWM, or TWM/CTWM. But not so much, as things come full circle.
EvilWM would look outdated and crappy under Slashdot threads in 2001 or close, because it looked something from the 80's, altough some bright users stated that it saved tons of RAM for applications.
Its clone CWM nowadays it's highly praised by OpenBSD users as a no-bullshit, floating-no tiling madness window manager (and by me too). It works, it can work without any mouse for every window action (even resizing), it doesn't need dmenu, you can use virtual desktops and search between opened windows with autocompletion. So, forget about RSI's, your hands can literally rest.
> Just in case you want an even more vintage experience.
Just to clarify, it's not about "vintage experience". Xfce is deceptively simple - it gets out of your way and let you do whatever you wish. The original settings are sensible as they are, but you also can customize it as you wish. It is pretty un-opinionated.