Osiris looks like some kind of frigate or destroyer (in the present-day sense, not like "Star" or "Omega"). And that isn't quite the Razor Basestar. It's the top section of the Razor Baseship, duplicated so it's also the bottom, and then superimposed on a TOS Basestar. When the first trailer leaked, I was kind of disappointed by how much of a kludge it was, but I played with the design a little since then, and the silhouette has really grown on me.
Weird about the Galactica. I mean, it wouldn't be too strange for it to have looked different 40+ years before the series and then modified in the meantime, except here and in Razor, we saw other battlestars during the war that looked like Galactica did during the show. It could be CG corner-cutting, but it'd be odd to design a variant battlestar and then forget to change or obscure the nameplate.