Since you couldn't find a manufacturer's mark on the gun, did you actually find a caliber stamping labeling it as a 45-70? Also, you only say "off-brand" ammunition....what manufacturer and loading? While keeping a single caliber designation, the 45-70 is essentially two different loadings....the "orignal" load which mimics the orignal blackpowder loads, and a "juiced up' version for shooting in modern guns capable of handling the additonal pressure. Even if that was a true 45-70 revolver, loading it with the higher pressure, "modern" loads may have been too much for a gun designed for the more mild blackpowder equivalent loads. Also, only one of your links actually takes you to a picture of the damaged gun, the other two link to an auction website