Nice find, to say the least. Now that you've raised attention on them you probably have the vultures coming out for them, if not now, maybe eventually.
I'm late to the party but I've read everything.. Anyone who thinks drilling a drum is going to increase value is not an expert.
Then you have the stained interior which provides ironclad evidence the drum was a single-headed drum.
You should buy this book:
[ame]http://www.amazon.com/Slingerland-Book-Rob-Cook/dp/1888408103/ref=sr_1_1?ie=UTF8&s=books&qid=1279502594&sr=8-1[/ame]
I don't have it but I've got a couple of other ones by Rob and they're excellent resources.
Lastly, if you do decide to sell them, you may be better off selling them on a well-publicized auction (ebay). When it involves drums that are this rare, your offers from known resellers and private individuals are--almost without fail--going to be way lower than what their retail value is. I do think you should post them on other sites such as Notsomoderndrummer.com, drumforum.org, and any other site that has collectors on it. There are vintage drum experts who aren't actively involved in selling who could certainly provide you with good info on their value, BEFORE you sell them. John Aldridge comes to mind..
Good luck! Not really certain about value other than to say rarity AND desirability creates value. This set definitely covers one of those requirements.
BTW My suggestion that you wait as long as possible and get all the info available especially from sources WITHOUT a vested interest in purchasing them is based on experience. I sold something to a collector and re-seller that I regret to this day, and I really thought when they were being bought that I was getting good money for them. Looking back I could have easily doubled or even tripled my money.
