I suppose you mean http://atari4ever.free.fr/hardware/zip/scsicnt.zip
I considered building one (before I found the old Megafile 60 I'm trying to get working now
. I went so far that I did some background research for this, checking for component availibility etc.
First, it seems that the board uses some very outdated components that are hard to find. It could be possible to replace these with more modern ones, but since I'm no expert in electronics, I came to the conclusion that I'd leave this to the experts.
Second, there are just the schematics, not the board design. I tried drawing the board with Eagle, and came to the conclusion that this should be left to experts as well.
Also, the board needs to be double-sided, so making one without access to a PCB manufacturing facility would be quite difficult.
Anyway, I think that this could work if someone with more solid knowledge of electronics takes the schematics, updates some components and makes a working PCB layout. Any volunteers?