If you can find old knife company bone, you will pay heavily for it. I have heard as much as $200 a set for old Remington bone.
You can do it yourself! The jigging part isn't has hard as it may seem, especially the nice, old looking, random jigging you see on vintage slip joints that wraps around to the edge of the bone. Here is an example of a new knife that Reese did...looks as good(IF NOT BETTER!) as any old bone you might be able to find.
NOTE...the jigging how it goes to the edge. You cannot get that look with jigged bone that you buy. Most makers will end up sanding off the jigging along the outer edge and the edge near the bolsters. On the other hand, if you do it yourself, you will get the full jiggyjigged look that is sooooooo sweet.
You can get a rotary 5/8" button burr from MSCdirect and bounce the jobby around on the bone till you are satisfied with the coverage.
The hardest part is coming up with a color that you like. Use Fiebings Pro. Oil Dye and soak the bone for a month OR I use a paint pot from Harbor Freight to speed up the process and can dye bone pretty good overnight. You can see what works for me in this thread:
http://www.bladeforums.com/forums/showthread.php?t=470663&highlight=knifehead+pot
Using denatured alcohol and playing with dyes and testing with white paper strips is how I am working out the colors.
In fact...I just jigged and dyed some yellow bone this week. This was plain white smooth bone from Culpepper & Co.