I'd call the agent and try to re-establish communication with the seller. In particular because the deal fell through, it would probably do more harm than good for you to try and contact the seller directly. If you don't remember who the Realtor was, then find your own Realtor and ask them to do some homework for you.
They should be able to get it put together for you.
Hope that's helpful!
...and if you'd like a referral to a great agent in your area, feel free to contact me at http://www.HernandoLuxuryHomes.com
and I'd be happy to put you in touch with someone.