Yes, those rifles were blued - no nickel and definitely not stainless from the factory. The good news for you is that these guns are not all that collectable - they routinely sell for about $300 - $350 on gunbroker. So, the aftermarket nickel job shouldn't hurt value in today's market.
I had one of these guns for years - actually just stored it for someone (and hunted with it some). It is actually a nicely made semi-auto 30-06. I've always felt they should sell for more than they do - never could figure this out. It did have a 20 round detachable magazine - held 20 rounds of 30-06. So, to all those antis out there that claim the AR is a "high-powered rifle", the Woodsmaster, with a 20 round magazine, is a true high-powered rifle.