Did I buy a fake Summicron?

I bought a Summicron on eBay about 4 months ago. Just right now I noticed the aperture scale reading marks 1.4 rather than 2. How can this be verified. I can’t find anywhere why it would be like this. Lens came with the Leica hood, cap, case and Leica E39 filter. Everything seems legit but I’m perplexed by the barrel aperture scale.