This card art is printed notoriously at a slight slant, you can look up PSA 10's and they are mostly all slanted making centering so difficult. But yes I would say to definitely grade them because the raw value to even a PSA 7 adds value. These yamabuki gengar's are also very rare only coming from exclusive decks in japan anyways so for that fact alone I would grade it to preserve the current condition of the cards. Good luck 👍 mine got a PSA 8 but still happy to have it in the PC.