Basically, I think you should measure before assuming your old bike and hub are 130 because there is one extra component on the outside of a modern hub, which means it has to be wider.
Also, I have a 6-speed Uniglide, and it is 126, and my reading indicates they went to seven, then eight speeds basically by making the spacers between cogs narrower, and stuck with the 126mm width. However, I did not review my sources prior to posting this, it's been a while, and I did not concern myself with 8-speed stuff back when I read it, because it's not what I have.
Uniglide is the general name of the 80's and 90's era freehubs with a threaded top sprocket. The modern stuf is called hyperglide or interactive glide (shimano HG-50 for example.)
Last edited by garage sale GT; 07-11-10 at 01:02 PM.