Perhaps if the two of you could get one (or two) out on the web, we might be able to interest a publisher (or maybe even Zirndorf). Just a thought ...
This could be really interesting--especially using the Playmobil as the modeling tool / animation tool (without explicitly marketing the book as Playmobil merchandising). You know, like a "Powered by Playmobil" footnote in the credits, but not overtly calling the book "Playmobil (TM) Adventures: Sally's Trip to the Zoo").
Most parents probably don't care about whether books double as advertisements for a product line. Though I have avoided buying Playmobil 1-2-3 for my child because I feel like I'm feeding her propaganda / trying to brainwash her to like Playmobil products.
I guess, though, calling a book "Playmobil (TM) Adventures" would make the book easier to market among playmobil users, especially if the majority of parents aren't troubled by (the perception of) advertising.
But, for high-quality stories, you might get broader respect (outside the Playmobil community, who would surely be attracted to the scenes) if the books use Playmobil for scenes, but don't use the word Playmobil on the cover.
I don't really know though.
-Tim