Yeah.. the C is def wonky but i also think it's legit..
Just based upon... most fakes are not intended to fool the experts, too much of an investment is needed to manufacture them to that level of quality, they tend to fall into categories of good fakes and bad fakes.. the bad fakes are not really intended to fool anyone, you're buying a Louis Vuiton handbag for £15 from Thoresby market, you know it's fake (the equivalent here would be a standard stem with a Syncros sticker) No point investing time, effort and money trying to fool the Parisian fashionistas when they're not the ones shopping at market stalls..
Good fakes take a lot of expertise and investment to pull off well, take fake Nike trainers for instance, they used to be terrible but because they're so ubiquitous there is a shit load of money to be made from convincing people otherwise.. organised crime becomes involved.. the profits are reinvested in tooling and before you can say bobs yer uncle, they fool everyone but the experts around the forums..
This stem would fall into the latter but it isn't in any way ubiquitous, in order to see any kind of return on your investment you would need to manufacture and sell loads of them flooding an already niche market.. i don't believe the margins are there to do so and there are a lot of different and skilled manufacturing techniques needed to pull this off to this level of quality.. it's not like pressing a button on your CNC and machined parts pop out the other end..