Yeah that's kind of just how it is with Redd, at least for me and many other people I know. While it would be funny if the game punished you for time travelling and heavily increased the rate of fake's, i'm pretty sure that's not something that's in the game. I'm not too bothered about getting fakes really, since I just use any statues I get to decorate my island, but I get that it could be really annoying if you're whole objective is to complete the museum, meaning fakes are pretty much useless. I have had all genuine works of art on a couple rare occasions I believe, and have had all fakes a lot aswell, but the usual rate for me seems to be 1 real and 3 fakes. That works fine for me though, since y'know, I can only buy one at a time anyway. If you're having trouble getting any real art and really want to complete the museum, i'd just check out some of the threads on nook's cranny here, since even a lot of the real ones go for insanely cheap now compared to when they were first released.