Oh, I'm pretty sure that when they dropped the 's', everything matched on a particular saw. But some of the ads could show the 's' even though none of the saws did concurrent with the ad(or not show the 's', but the saw did at the dealer etc). Doesn't matter except to a hardcore collector.I can only speak for this model of saw but these saws had a metal nameplate with the brand name painted on it and the year and ss number stamped into it. I have yet to see a name plate that has a different spelling than the recoil and clutch cover stickers on intact saws from that era.
My 910's all have the 's'....but I was told there were a few found without......not sure I believe that without pics.
Kevin