"On Parole", "Motorhead", "Blitzkreig on Birmingham (live)", Iron fist & the hordes from hell", "lock up your daughters", all of this 5 albums existed before Overkill album, but public saw them (some of them) a years later, so what? Those two BLitzkreig and Lock up... are Eddie releases and he got permission from the band to release those two, I got that confirmation from Alan Burridge. So they are official, and they all existed, only they come infront public eyes later, so? I can make picture now and put that in store in 2067, so people can talk about it, write about it in 2067, it will be always picture from 2013 because I painted it in 2013. Or if you want one more example, simple question: Is it your birthday on a day when public saw you or when you came out from vagina? Simple question. Metaphoric but I hope I helped you to understand. Cheers!