replacement springs for DT360A (Thermal Phase)

Good evening from Germany 

I´m thinking about replacing my rusty original springs from the thermal phase shocks with new springs (maybe YSS). Are there any experience what type from YSS will fit to the thermal phase shocks from my DT 360?

I measured the following: OD 55 mm, ID 43 mm, length 225 mm, wire thickness 7 mm, 16 windings.

New chrome for the rusty parts will cost nearly 200 $ in Germany :(