The only sun Topre board that I'm aware of has this layout:
Show Image
(http://geekhack.org/attachment.php?attachmentid=5845&stc=1&d=1258784436)
And here is the actual board and as you can see the actual boards layout is a little different than the picture above. This one is the closest I've come to finding that layout in an actual board.
Show Image
(http://geekhack.org/attachment.php?attachmentid=5846&stc=1&d=1258784436)
If I remember correctly the layout is a 5e there was also a Japanese version of it as well. You can see it in this picture:
Show Image
(http://geekhack.org/attachment.php?attachmentid=5847&stc=1&d=1258784595)
That one above is actually for sale right now on Yahoo Japan for 11,000 yen which is not a bad price considering it also comes with a KVM in a 1U rack mount package. That has been tempting me for awhile now but I already have the MD01B0 which is essentially the same board and I had other boards I wanted more.
I don't have much experience with Sun Microsystems computers (SunOS, Solaris) but these Topre sun keyboards work with an IBM-compatible system?