I've not worked with Omega guns, so I'm only guessing -- but the main difference between the versions is the presence of a decocker mechanism. In the standard 75B models, the only difference between a DA/SA gun (that isn't decocker) and the SA gun is the disconnector link, which is removed in the SA model.
If you find a better answer, you'd want to know if the standard SA triggers (the blade itself) and the larger (easier to use) safety lever is also compatible. (I have seen that there are larger levers for both models with a single safety lever and those with ambidextrous levers.