I also picked up a shadow during the recent sale and just received it today.
My recoil spring was the same as the OP and is a round wire spring and not the flat spring. ( same bent plastic guide rod as well)
Maybe CZ has phased out the flat wire recoil spring?
Yes they have. Because the flat spring like I pictured, will not work with the stainless guide rods. My older SP01 still has the flat spring, but the replacement are coil. Nothing wrong with the plastic guide rod. Ive put like 5000rds and haven't had issues.



























