I was finally able to get these files although not by downloading the zip. If anyone is still having trouble get the git utility https://git-scm.com/ and install it ( I believe I left everything at default) and then in the git command window type the following: git clone --depth=1 https://github.com/microsoft/Microsoft-Rocketbox.git

It will clone it to your root directory and then you can move it anywhere you like. This is not a zip file so it's not compressed - it's 23+GB. The .fbx assets themselves are 10GB so if you don't need the rest just toss them out.

I think they came out pretty good when rendered with an .hdr and one light. I didn't do anything special in the material room except what the OP said in the first posting.