Mark, some driveline shops may be different than others but here is a sheet showing how the driveline shop I use wants you to measure. Tom knows the rest of what works and don't. He's been doing this for 30 years. He has some "spares" standing around and can pull one and shorten it, put what ever ends you want on it and balance it. Here is how most are measured.
http://i140.photobucket.com/albums/r19/LutherParris/52Panel/img011.jpg

I work part time for Tom and he is a super guy. He makes and ships driveshafts everyday. Vintage, racing, off road vehicles and many many more. If you have a driveshaft and not have a shop close by call Tom.

Here is their web address.
http://carolinadriveline.com/


1937 Chevy Pickup
In the Gallery
1952 Chevy Panel
In the Gallery
More photos
1950 Chevy Coupe
Pictures!

I'd rather walk and carry a Chevy hub cap than ride in a Ferd.
I can explain it to you, but I can't understand it for you smile