You can use acoustic piano parts from Vandaking. Much easier and cheaper than trying to find originals. Original springs will be just as old as the ones you want to replace anyway. Make sure you buy springs meant for spinet or console pianos. NOT full size upright springs. The Wurlitzer action is just a miniature acoustic piano action, (sort of) these parts are interchangeable. I think they only charge .14 cents per spring!
These spring are a pain to change. You really should remove the whip assembly from the piano first. Use wood glue to replace. Make sure you get all of the old spring out. They do sell a reamer but you probably do not need it. I would start with the few that are not working properly, don't just take all 64 out at once unless you really want to go that far. Needle nose pliers help remove the old springs. (Wrap the old spring around the pliers and lift out) Are you sure that the jacks just don't need protek on the center pins?
The rail pins come in 2 different sizes too, match up the closest possible. (I think it's the shorter one) If they are too long the keys may stick. These are just pressed into holes, but a drop of glue may be needed if holes are oversized. Be sure not to mount crooked, they are oblong.