The PM2535 has the GPIB already fitted.
It comes with original bound operations/programming and service manuals.
The System21 modules comprise:
1x PM2101 GPIB interface (no front panel)
11x PM2120 Universal Switch
3x PM2132 Digital Output
2x PM2198 PSU
1x PM2130 Digital Input Output
(18 modules in all)
If you need this heap shipped in the mainland UK I can do that for £10 I think. Say £130 total.
Send me a private message if you want more details and/or photos.
Location is GU25