Hi Muks, a nice selection, even if they may be reprints.
I think even the top row, first stamp might be a reprint, as SG Catalogue lists this value/design as being red, whilst the reprint is found in yellow-green. The top row, second from right may be a reprint of N24 as SG describes the reprint as having a taller, thinner figure "1" like that on your stamp. Still an interesting range of topics shown, despite the likelihood of them being official imitations or "reprints", for sale to collectors.
I acquired many such stamps not only from N. Korea, but also Bulgaria, Hungary, Romania and the pre-unification Emirates in stamp packets from Woolworths (department store now gone from UK high streets) when I was still at school. They were, to my eyes, colourful and exotic, and probably contributed to my later interest in travelling to many countries for work. I even lived in Al Ain for 4 years!