Clavi
788
Hi Karmin
Hi Karmin,
Your name sounds familiar from "somewhere else" 
Nice K916 memovox collection, I particularly like the 876 (which is the one pictured her, so not missing, I guess you mistook it with the 872).
The 876 is rarely seen and quite rare.
the others are great too (nice blue orange dial on the 873)
Back to your question, and although I am not a sepcialist in 'master' series, I belive that the 'curved' writings are indeed more a sign of period rather than model.
I 'think' the one you show at the bottom (gold, double curved writings, 'reveil') is the oldest, i.e. the first 'master' memovox. Then, I think your version comes in second (before the 'master reveil' was introduced, the 'master memovox' was available in silver dial. after the 'master reveil', the 'master memovox' came in black dial), and finally there was the black-dialed master memovox (hand wound), and the silver dial master reveil (auto), until the time when they were (sadly) discontinued to be replaced by the 'monster' memovox (aka 'compressor').
Not sure this is 100% accurate as again I am not too focused on modern (or recent) series, but that is at least what I think.
