http://www.error-ref.com/transitional-reverse-1988-1c-with-reverse-of-1989/ The last two images are a bit too grainy to make the correct call. Would it be possible to post clearer photos of the FG and maybe an up close of the AM of America?
Though the image quality is still grainy, I would agree, as the top of the "A" and "M" are rounded rather than flat: (From https://www.cointalk.com/threads/1988-cent-is-this-a-rev-of-a-89.263261/) However, for final confirmation, would you mind posting a not-so close up of the area of the initials and seeing if the "A" and "M" seem rounded in person to you?
Ah! With clearer pictures, I see what you mean. Could you take a picture of the "FG" initials, slightly zoomed in just as you did above, just for final confirmation?
That thin G missing the serif (slight projection) makes me think it is indeed just a regular 1988-D. I wanted to make sure that's the way it looked (in your first picture, the G was pretty thick). Sorry for asking so many pictures, just wanted to be sure. I wish you luck on finding an 88 w/ 89 reverse, though! At least you've got plenty of resources for reference now .