OK, found the correct emails. Remember, this was for the 256MB Radeon card, but the principle should be similar.
In short, they told me to do the following (and this seems to be what you did):
#1: Install the Picasso96 graphic system following its documentation. Choose Cybervison 64 3D as the graphic card.
(I installed P96 2.1c package)
#2: After the Picasso96 installation, start Picasso96 installation once again and choose the "Update an installed version". Select only "Monitorsettings" and choose the frequency supported by your monitor.
#3: After successful installation you need to:
a: Find the CVision3D and CVision3D.info in the DEVS:Monitor drawer, rename these files to Radeon and Radeon.info respectively.
b: Change in the tool type window of Radeon.icon:
BOARDTYPE = from CVision3D to Radeon.
c: Copy the enclosed Radeon.card driver to the Libs:Picasso96 drawer.
(I copied the one from the 1.33 package)
d: Double click on the Radeon icon (in Devs:Monitors drawer).
e: Start the Picasso96Mode program (in SYS:Prefs drawer) and select:
Attach setting to Board0: Radeon.
Exit Picasso96Mode by SAVE.
This is where my setup failed and I got "NO BOARD" reported, which seems to be the same problem you have.
I then used the MedConfig program to dump an error log, emailed it to them and they sent this back:
Thank you for the MedConfig report.
You have not updated drivers (running quick install script) from MM CD 1.33.
Copy
http://elbox.com/download/newest/pci.library to Libs:
http://elbox.com/download/newest/Radeon.card to Libs:Picasso96
http://elbox.com/download/newest/sb128.audio to Devs:AHI
and all should start to work.
It seemed that the old installer wasn't putting the new files where it should. After manually copying them I got the Radeon to show up in P96.
However, the card still didn't work, but they also spotted this:
Your Radeon card cannot work because you have wrongly setting of the WINSIZE jumper on the Mediator Core Logic board.
This jumper has to be closed (set to 512 MB, not 256 MB).
Change it and your Radeon will start working with pci.libarry 8.1 and with 9.0 (with added memory).
So, make sure you change the tooltype for the monitor icon (4b), try manually copying the correct files for your card into the various folders mentioned (libs: & Libs:Picasso98) and finally try playing with the WINSIZE jumper.