I couldn't find nesselro being sold anywhere on the Internet but did find a recipe for homemade nesselrode. Hope this helps.
Homemade NesselrodeBoard: Cooking Club at Recipelink.com
From: Betsy at Recipelink.com 11-10-2007
MSG ID: 0082306
MSG URL:
http://www.recipelink.com/msgid/0082306