You sure it isn't NW? Northwest Metal - Seattle, WA. No matter how it is marked, it would never be used again if it were mine. Never hammer something into a rifle. Everything should fit correctly. If it doesn't, then it's time for the "oddity bag" or gets deep sixed. More than likely that clip is just defective - either from manufacture or from some type of abuse/alteration. Just don't use it anymore.

As far as .308, I don't know anything about them but I imagine that unless you have one of those shorter Italianicon rifles, the spring should be the same length as the 30 06 Garandicon. I'd contact the supplier and get their input. A new spring shouldn't set, no matter how much or little.