Hei!
Check this site of UK Defence Standards:
http://www.dstan.mod.uk/
The site has at least a full list of all DTD specifications ever issued:
http://www.dstan.mod.uk/dtd/dtd_opts.htm
At their "Helpdesk" (see the upper row of page) there is also "Customer services". Norwegian government institute like aviation museum might be able to get copies of DTD without charge. I really don't know, I tried to look into the issue few years ago when some DTDs would have been needed. Eventually it turned out that the aviation museum already had the standards in their library!
Let me/us know if and how the DTD copies are available.
HTH,
Kari