I dont have 172, but at least i put a few up. So if anybody is looking for the Harrahs E.Chicago numbered GO chip from 2002, nows your big chance.
Also, some of the new Phoenix GO chips and slot card.

Heres the link:

http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&userid=chip-a-holic&include=0&since=-1&sort=3&rows=25