I didn't grind hollow first. It would be tricky to grind in such a way that the step still comes out right. For a simple faux frameback you could so something like this. One issue I can see is that it could perhaps be more difficult to keep a consistent flat grinding surface if you have to grind in an existing hollow grind.
I used a guide that I screwed on to the steel blank to help keep tight grinding lines, and moved the guid against the side of the wheel. It's not something I do often, because it is a pain in the neck to do a good grind like that. It is very time consuming.