SGI Indigo keyboard / mouse / converter wanted

[Jules Richardson via cctalk]

Hi all,

A friend of mine has just acquired an Indigo (R4k with XZ graphics option), 
but of course it's the usual story and the keyboard/rodent had been lost. 
In absence of the genuine items they'd still be happy with a USB converter 
(at least for the time being), but it seems those are difficult to come by 
at present, too.

Does anyone happen to have a surplus converter suitable for these machines, 
and/or keyboard/rodent? (according to sgistuff keyboard is p/n 9500801 and 
mouse p/n 9150800)

[side note: they mentioned a USB converter, but I'm pretty sure years ago 
someone had implemented an adapter to PC-friendly PS/2 parts, too. I'm sure 
something like would do the trick, too]

thanks,

Jules