Hi Claudio,
I think the first two are fakes, as I have never seen a cut-out version of the pilot badge come out of an estate, and the design of the Taube looks to me like Wilm, not Juncker. The first Bavarian observer I don't like, I think the engraving looks weird, and it should have a Strahlenplatte, not a smooth one. Also, the hooks for the attachment of the enamel device don't look right, and neither does the hollow area for the pin attachment. The second observer has a good chance, I like the style of engraving, the reverse looks good as well as the hardware. Do you have a close-up of the engraving?