Search for "Sleazy Steve's Soggy Bottom Fly Shop" you can probably use his foam shaping tool for cork.

Have you tried the Dremel bit for holding polishing wheels and cones? It has a reverse thread that you can screw into the cork.
[url=http://dremel.com/productdisplay/display.asp?sku=401&color=666666:9fe96]http://dremel.com/productdisplay/display.asp?sku=401&color=666666[/url:9fe96]

I have not tried it yet so I cannot tell you if it works or not.

HTH.

[This message has been edited by classicflytyer (edited 31 August 2005).]