Is this a Danish chair?  

Apologies for the poor quality photos.
It has a curved hard seat covered in pale yellow vinyl.
There is a stretcher at the back.
Here is a back view:

Not G Plan
could be Nathan, or Younger perhaps.
(if Younger then better quality than the Nathan version)

Not sure it's G Plan
But I would say it's generic British. If not G Plan, maybe Nathan?
Have a look on the link below for G Plan archives:
http://hwfurniturearchive.bcuc.ac.uk/asset-bank/action/viewHome

Grand job fellas
Thanks very much. They are indeed identical to these in the link below, which are described as Younger.

Are they worth 15 quid do you think?
There are 6 on offer, and I am tempted to sell my Dyrlund chairs (pictured below) as there are only 5 in my set and the odd number offends me.
http://www.chairsandskyscrapers.com/a-younger-dining-chairs.aspx

I'd Keep
the Dyrlund no question!
Hold out for a single..
or hide one! 😉

Well,
that's settled then!
Thanks for your take on it.

5 dyrlund chairs
I would Need Theese 5. Do you think about selig them?
Best greetings Thomas