For Base Set what I look for first is if the N in EDITION lines up with the middle of the gold rectangular box. If it does, it should be real. You can take a picture (or better, scan it) and zoom in reeeeeeally close and see if the stamp looks smudged. A real stamp should look incredibly crisp even up close. I think your cards are okay.
I didnt think there was a problem. I was only made aware of fake PSA stamping recently so I have become slightly paranoid that I may have a fake stamp due to its value. I guess my problem is that Im not a professional when it comes to Pokemon cards so I was seeking reassurance that they were authentic?