It's for sure Russian dipped. The Russian dip is usually black and thicker, almost like frosting on a cake. FWIW here is one that is close in serial number since it's in the same suffixed letter block. The Spreewerks were built in sequential order (1-10000) by No letter Suffix, Suffixed alphabetically (a-z), then prefixed alphabetically (a-b). So this one would have been produced <5000 after the one you posted.