JenB,
I believe the impressions on the backs of the two stamps are just from the design being pressed into the paper. This was common on this issue. I don't see any grills, but the images are small.
More on color: This issue came in a wide variety of colors. Many collectors who acquire a group of them see a wide range of shades in front of them and naturally think they might have one of the rarer colors (pink, rose pink, pigeon blood). Your stamps appear to fall in the rose shade, and on the paler side. The paler rose shades can look close to "pinkish" but the required pink pigment is very distinct, and not apparent in your stamps.
I didn't want to do this in my first response to your thread, but I'm going to post an image of my #64/65 color set. The reason I do this reluctantly is because your middle stamp may look close to my rose pink. If you look closely (maybe put your eyes six inches from the monitor like I do), and stare for a while at my image, you should see a distinct baby pink color in my #64 and #64b. I don't see this color in any of your stamps.
Beyond this, I think your best bet is to have someone else look at your stamps in person if you think you might have a color other than one of the #65 colors.
