Mike AR,
There's a .50ca. barrel on ebay now that would fit your New Englander.There's a little over a day left on the auction. It's at $26.00 right now. This is a T/C High Plains Sporter barrel and it's basicallythe same rifle except the HP Sporter has a pistol grip stock. This barrel will drop right in the New Englander stock.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7216102330&rd= 1&sspagename=STRK%3AMEWA%3AIT&rd=1

Good Luck and keep us posted