In case anyone here needs it, I just put up a HUD out of a '91 STE for sale on eBay. It's a compelete set, the unit itself, the metal brackets to bolt it in, dimming control switch, and even the dashpad if you want to install it on a GP that didn't come with HUD. Check it out:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1838679919