Here's the old school tech. First I got another spring from Jim Finn. I cleaned it up and put it my vise.
wIth a gasket scraper I removed the end pads. Took them to my bandsaw and cut them in half so
that they were half as thick. Then I took the (new) spring to my table router and removed 3/16" of
material in the areas that you can see in the pictures. Then, with my bandsaw I removed 3/16",
material from both ends of the spring. then glued the modified pads back on the ends of the spring.
By the way, It is very easy to remove the old spring as long as you soak all bolts for a few days.
The actual removal of the spring took about one hour and less to put the modified one back.
The only thing I regret is not taking more off the ends, as that seems to be the way to lower it more.