Both table and chairs have more of a 70's feel to me. In my mind Danish Modern wood styling devolved from the more fluid and elegant forms of the 50's - 60's, to more orthagonal, boxy, chunkier forms of the 70's. I believe lower manufacturing costs and more efficient use of wood were the prime reasons behind this shift, but there could also have been a design aesthetic shift in that direction as well.
Names like Domino and Gangso come to mind for this style, not that I'm saying your pieces were made by either of them.
Lower manufacturing costs, boxy, and chunkier does not always equate to "cheaply made". There are some Wegner and Moller designs from the 70's and 80's that I think are a far cry from their best work from the previous two decades. Those framing members tend to be straighter with less fluid cross sections as well. Very few would argue that Wegner and Moller chairs from that era are cheaply made.
Many of the 70's Domino and Gangso pieces I've come across are still going strong from a construction perspective. It's hard to give a quality assessment for your pieces based only on photos.The easiest and most up-to-date reference for desirability and value would be to check the sold listings on eBay for the last three months. You can also check Liveauctioneers, but 70's Danish hasn't appeared frequently in most of those auctions yet.
I qualified my previous comments with "In my mind . . ." Others may like the styling of the 70's.
I agree with cd. To *my* eye, they resemble pieces imported to the US in the '70's or even through the '80's. That said, they appear well proportioned, well cared for, and of fairly high quality for the time. I don't see any definitive evidence, however, that the table and chairs are a set. Or even from the same maker. That doesn't bother me in the least, though, as they work well together even if the fabric might seem a little drab or dated.
If, as you mentioned, tugboat, you got them at a good price and they fit your needs and environs, I'd say you've done well. At very least, it's a good "user" set until (if ever) you decide otherwise. You likely won't lose anything by living with them for awhile.
Here's what appears to be the armchair version of your chairs. The listing says its marked on the bottom with "GM Made in Denmark". A few G- moblers and mobelfabriks that could be possibilities.
https://www.liveauctioneers.com/item/44049328_danish-modern-upholstered-...
If you need any help, please contact us at – info@designaddict.com