Greetings,
I removed the #25 spring from one of my machines.
It measures 0.055" wire, 0.35 Outside Diameter, 0.65 Free Length, both ends closed and ground.
I searched McMaster-Carr and MSC and could not find a suitable substitute.
If Cunningham has these for $2.00 each, it would be money well spent.
Cheers,
Dave