Since these cards aren't tournament legal, though, technically it doesn't make a difference what power level they are scaled for...
...
...
... since you can always try arranging with the tournament hosts to errata these cards so that they fit into their respective power levels!
I mean, think about it. If you're hosting a tournament and it matters enough to you that these cards fit into their respective generation's power levels, you can always CHANGE them so that they DO! And if you aren't the one hosting, you can still use your powers of persuasion and logic and reasoning (TM) to make your case for why these cards SHOULD be errata'd, and if the tournament hosts agree, then they can change it! Since no tournament that these cards are used in will ever be official, you don't have to follow the exact number of the card if you can propose an errata.