Ah, it can go into the DLL, and it's already there. The problem may be that there is conflicting information about which resource ID - https://msdn.microsoft.com/en-us/library/aa374224(v=vs.90).aspx says it should be 1 while your link says 2.

python27.dll has the manifest as resource 2, so if that is incorrect, then that could be a reason why it's not working. (Looking at the search paths in that link above, there are other potential reasons if it's finding a compatible assembly in the MATLAB folder, but it sounds like that's not the case.)

I guess we need someone with the patience to go through and figure out exactly whether it should be 1 or 2. That person is not me, sorry.