The reverse of the question I have been musing on as a first time buyer - how much to ask for and how much to be absolutely required. I too am frustrated by the lack of the most basic information in a lot of the ads. The more info in the ad, the more likely I am to take any interest to the next step, particularly if not in the "local" area when the costs of the investigation and transaction go up (postage, long distance phone, travel/delivery). Ads missing the most basic stuff, or are not straightforward about it, are suspect - they will have to come up with it sooner or later, why not be upfront? I will only investigate those when other options are exhausted.
What I would add to Don's list is to compile e-formats of all the info into a complete data package. Along with a description, a list of modifications & the vendors of those mods, as much of the service history as known, scans of the logs, pictures that document and enhance the written or verbal description, the FAA info. The results of a current title search would be a nice bonus and could possibly shorten the transaction time. ( If anyone is reluctant about copies due to possible fraudulent use, they can be electronically "watermarked" as copies or with the aircraft serial number). An analogy would be a prospectus for an investment.
This can then be disseminated, quickly, in the format the interested party can handle - web page(s), direct transfer like e-mail or fax, or burned to a CD or printed out for mailing.
