I'm painting my house now and the siding was really dried out. I'm using Ben Moore's Fresh Start. I used to be a house painter and I'm impressed with it.
I would also drill the rebar in. Would it be helpful to mix on a platform so you could dump from the mix bucket instead of scooping it out ? Maybe use an orbital sander to vibrate it through the funnel faster.
I have to do the same thing this winter but I dont have the extra wide bottom plate...