Mike, You may want to try to contact Seagrams as they may be interested in purchase. Or you want want to try a liquor auction? Here is some links on ebay which may help give a ballpark figure of empty bottles. You may be onto something with full ones though. I will keep looking...
eBay - Seagrams, Distillery, Advertising, Collectables items at ...
Hello, I found this site to be interesting on antique Seagrams bottles and other Seagram collectables.
You might wish to contact Whisky Magazine, as they can refer you to proper parties:
Whisky Magazine : Contact Whisky Magazine
Also, you can contact "Wine Magazine" (address and telephone number below);
See the link below re: article in "Wine Magazine" about a whisky auction that was held in South Africa:
Ramsay, Son & Parker (Pty) Ltd, Digital Publishing3 Howard Drive, Pinelands, South AfricaTel: +27 21(NNN) NNN-NNNNBR>Fax: +27 21(NNN) NNN-NNNN/P>
Hope this helps.
Peace, Love & Happiness,
The Mystic Wave