Concretion Not Erosion

Hello All, I am in Washington D.C. and new to the forum, but I have been collecting Portable Rock Art for some time, and like I am certain, everyone else here, it makes me crazy that people can not see the art that I see. I had amassed a large collection that I had left as found, but I decided to find just one piece everybody could see was crafted by hand, with no ambiguity. I decided to clean up one of the pieces I had found and see if I couldnt scrape the sediment out of the lines. I put the blade to the rock, and a huge chunk fell off. Beneath the sediment was perfectly preserved carving. Shocked, I cleaned the rest of the stone to find a perfectly preserved figure, (it is the larger dark stone in the photo of the two faces).
All of this time I assumed detail had been eroded away, but instead some had been preserved through concretion
I went through my collection and found a few more that were encased in sediment or calcite, I dont know my geology, I can tell you that it loosens up with water, and that a steel razor blade will scratch the sediment, but not the carved stone beneath. I have found them in a few locations and made from a few different types of stone. Enclosed below is a 6 panel photo showing the stone from as found to excavated. I am not carving them, if I gave you a blade and the same stone, you would end up with the same figure.
I am confident that the stones are carved on both sides, but I have only cleaned one in most of the pieces I have found, keeping the original concretion and cortex in place an intact, with carving still encased below.
Another important note is that the stones picture are where I have stopped cleaning them, there is certainly more detail that is not revealed, as well as some lines that should be cleaned off, but they are as far as I can clean them with the tools I have.
I have cleaned 60-70 maybe more, I have lots that are partially cleaned, and a few I have barely touched, in hopes of getting a professional involved, the panel of a green stone I believe resembles a smilodon or another large cat.
I have no idea what to do with them. When I found other portable rock art, I was told it was just a bunch of rocks, and now I am being told that they are natural formations that just happen across several different species of rock from different locations. I have repeating themes and figures all resemble Native American imagery, aparently randomly. I have as many photos as you would like, I would love to get some thoughts, I could show you thousands of them. [You must be registered and logged in to see this image.]
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Here are a few more
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These certainly are interesting finds, but I am unable to qualify them as ancient portable rock art pieces. Your observation and good effort are noted though, and I do not have a 'natural' explanation for the groves present on your finds.

The find here, (bottom right box, upper stone brown flint?) has some clear evidence of (not much evidence) modification, agency, cognition, and has some very basic figuration possibilities.  
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