It sounds like a great car, love the Mahle gasburners. CIS injection?
Silver metallic may not draw as well as a 'period' 70's factory color like in this Ebay auction, but at least take some comfort from this hammer price a couple months ago w/ similar mileage-
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEWAX%3AI T&viewitem=&item=250270385691
This price looks dear but another comparo in exc condition:
http://www.heritageclassics.com/porsche/73bei911t/Page.html