With making a Garibaldi-"Franenkstein shirt" being a shirt made up from several commercial patterns, I just wasn't feeling the way the back was progressing with the patterns I have gathered so far.
Although I haven't found any photos/illustrations which are speficially of the back of Garibaldi shirts, it seems to me the common back piece of 1850s and 1860s bodices have curving side-seams, so that the main back piece forms a sort of triangle. I really like the look of that cut too.
So in order to get that look I'm adding another pattern to the mix: Simplicty 4900 .
Simplicity 4900, which I have borrowed, has that triangle back in its dress pattern. Although it doesn't have the drop-shoulder I wanted. But somehow I managed to trace a new back pattern piece by blendingthe back from Simpilicty 4900 with the drop shoulder in the Very Easy Vogue V8193 back piece.
I don't know how I managed it, but it seems to be working...