I've found what appears to be Base64 inside of a PE header resource (.rsrc) which I've placed in this Gist.
However, if I use a Base64 decoder, I end up getting a lot of binary data which appears as "gibberish" in the Base64 decoder web app. This means that either it is not Base64, it is modified Base64 OR it is deciphered to binary data (an embedded PE file).
I am not sure how to take that binary data and parse it into its own separate PE file. I'm only familiar with Base64 when it comes to ASCII text. I've tried copying the data and pasting into a hex editor like HxD and WinHex but neither have allowed me to paste the decoded data in.