The good part first: It’s a Lemania movement. Cal 19. The not so good part is that this watch movement was originally installed in a pocket watch case. Someone have fitted/converted it into a wristwatch case and sold it as a pilots watch. These “conversions “ are very common. Sellers, especially in the former east block countries, are pumping these out. Lemania never fitted these movements in wristwatches of any sorts. For pilots they used their cal 15 movements mostly. To your questions: I guess my questions are 1) is This a Lemania Movement and if so when would it have been made. 1930s-40s. 2) Was it common for cases and movements not be signed during this time period. No. Your case is not original to the watch 3) Does my assumption of the case material being nickle plated brass? It could be. 4) My assumption that this is a pilots watch appear to be correct? No. It has been converted from a pocket watch into something people of lesser moral is selling as Pilots Watches. They are not.