You might try doing a bit of straightening before you attempt to pull the sliders out. Maybe putting a 5/8" diameter rod [same diameter as your front axle] through the axle holes and strike the rod with a mallet. Don't know who can supply new springs but simular or exact springs can be found for most any application in the Century Spring catalog. The trick is to determine the wire diameter, the O.D. and I.D. and the number of coils in the original spring. It would be nice to be able to have the "free length" of the original as that would make specing it very easy, but old collapsed springs are far shorter than when new. Good luck.