Hey there Bill, interesting question. I surely imagine there would still be alot of those sorts of things out there, and for the rarer, good ones, prices would be substantially higher than most other varieties, as is anything Luger. I have not collected any myself, but on the topic of 'toy' lugers, i'm currently mucking around with a full metal replica luger, that my nephew has asked i fix up for him. Not a bad replica, strips in the same basic manner as the original and he wants it as a WW2 era pistol, so it's copping the correct wooden grips, proper mag/end, markings etc. It's coming along quite well and should be good when done, i've actually seen people collect these types of things. If you're a complete Luger fanatic and have your eyes on some, go for it mate! Something for the collection and if they take your interests, why not?!
The candy filled one you mentioned - i'm going to take a stab in the dark and say 60's?
Blake