Some info
The Heywood Wakefield company can be traced back to 1897, so obviously they made a lot of traditional furniture before they started designing "modern" furniture. You can commonly find old baby buggies on eBay, for instance. So, not all HW furniture looks like the kind of stylized furniture in this thread. The vast majority of interest in HW furniture these days is in their modern furniture lines. But they did make good quality traditional furniture before they started making modern furniture.
Usually each piece has a burned in marking of HW with a Eagle symbol.
Because HW became so popular, a lot of companies started making knock-offs. I have an example of a knock-off and it's almost a dead ringer for the original. The sure-bet way, if there are no markings to tell an original from a knock-off is the finish. Nobody could duplicate the HW finishes.
Around 60, 61, HW started moving into a different design phase. They started making "danish modern" styled furniture and used dark finishes. They also started making furniture that looked more like Paul McCobb and George Nelson designs, more angular than streamlined. And the finishes had names like Sable. I had a sable piece. This period of Wakefield is not very popular among HW collectors, though.
A lady wrote a HW book about this period a couple years ago. I believe it was called Heywood Wakefield, Danish Modern and Beyond, or something close to that. The cover shows a danish modern style living room set and I own that set and was going to post it here when I got a chance.
I hope this info helps you out a bit.