I have to chime in and say this is a perfect mold to do what you have accomplished. 100% custom awesomeness!
This looks INCREDIBLE and I love it to pieces. This could be the best ark custom EVER! Everything is ingenious and looks really clean so far. I hope you paint him eventually - toy or cartoon colors? Also while the scratch-upgraded head looks really good and fits the project's direction perfectly, have you considered the 3d printed design by Sam's Forge?
Bumping this because I was looking through looking for what Ark customs other people have done and I am FLOORED. This is next level amazing; I can't wait to see the finished product.
More pics please!!!! Loving everything shown so far. ...also tell us you plan to sell molded copies of all the parts so we can replicate this build. [waves $$$]