Chocolate is recessive, so if you breed two chocolates together, you'll get chocolate (though there are some unshowable possibilities like lilac and chocolate tort if the breeder wasn't careful about what they were breeding)a chocolate and white Dutch buck and doe.
Take it from someone who bred Harlequins for many, many years - perfect Harlequins never happen. Even grand champions are only "good enough to beat whatever else is at the show today."From what I can see, your animals stand as good a chance as any of producing something showable.She had some papers on the Harlequins but I'm not sure how good they actually are. The markings on the does aren't perfect and I think the buck is a Japanese/Magpie mix.