I just did a quick online search of some of my local junkyards and came up with 3 possible axles (again, I don't know what the differences/compatabilities are between years and models).
One is a front axle w/ housing off a 99 D2 w/ 76,000 miles on it for $600
The other is off a 96 D1 w/104k miles for $150
One off a 98 Disco w/92,000 mi for $300
So, they're out there....