Regarding the fakes (as opposed to copies) I have notised that the UK market is flowing over by them, worse than any other market I have looked into.
It is no surprice that may of those fakes reminds of some older Zenoah saw....
Yes, unfortunately the government had the great idea of getting people to install log burners, it was great for the first few years, made a fortune selling firewood, now, however, there is a huge increase in the thefts of arb gear, one notable case is where a forestry worker had left a 660 idling whilst he walked a few feet away to get fuel or a felling aid, some people turned up on a motocross bike, one jumped off, grabbed the saw, jumped back on and sped off, another case is the rise in thefts of lumber, where whole stacks of 20'x2+' have been taken (without cutting up), these saws have flooded the market, along with stolen stuff, and all are fetching premium rates, as the homeowners don't know what they are buying.
Back to the 543: if it has rubber AV, this is a huge step back for husky pro saws, husky springs have been fitted to most saws (can't remember if the 335/338 have springs) and these are superior, the saw IMO is a regression in technology, it may prove a great saw, but, and I hate to say it, I think stihl has them beat with the 241