I was worried about this but think it turned out pretty well with a simple approach. I followed the steps posted by others on the forum, and think we can call this a "If I can do it, anyone can"
I started with an mdf base, sprayed it with a grey primer then Camo Khaki Rustoleum.
Next, I used a 4d finish nail, hammered into a small 1x2 handle, and scored the mdf in regular patterns for the joints using another 1x2 as a guide. I also hand scored a couple cracks.
Finally, I mixed up some water and about 6 drops of india ink and worked it into the concrete. overall I think it looks fairly good.
I am wondering now if I should clear coat it with Rustoleum Matt spray like I do for the building after painting. Thoughts anyone? I appreciate any other feedback or suggestions as well as I hope to button this up and add details.