I can't find any trace of them (either as 'Smash the Nazi Navy' or their alternative title of 'Crush Adolf') ever coming up for auction, so there's no reference point to base a price upon. (Further, since they were produced in New Zealand, there probably aren't that many copies in the UK).
However I've attended countless auctions and seen what many WWII items go for and I doubt that they'd fetch more than a few pounds.
Sorry!
For anyone who wants to see what they look like:
http://mp.natlib.govt.nz/detail/?id=39731&l=en
(BTW: You don't also post here as Sincnoel, do you?
http://www.theanswerbank.co.uk/Quizzes-and-Puzzles/Question283810.html )