After researching these, I can only find 12 registered examples of this prefix. Now there are 19 with these 7.
Remember.... just because there are only 12 registered doesn't mean that more do not exist...many people do not like to disclose what they own. As for grade on the registry there is only one note TPG that has a lower grade than your notes...all have been graded higher. I also think the market conditions will not warrant the cat price, but who knows if you snag the right buyer...good luck and nice find.
As for selling them, there is the trading post on this forum, I believe Colonial Acres in KW is starting to have regular auctions, you may ask them if they take items or only sell what they have in stock, and some of the popular auction houses...doubt you will do well on Ebay
If you do end up auctioning them, I would make sure that you can place a reserve bid on them...you may be shocked if they sell for much less than you think they should go for....