Is there a guide for using gtk-rs on Windows with MSVC? If not, can you walk me through it 
AFAIK buiding gtk-rs relies on the available allready built binaries from GTK. They are not compatible with the MSVC Linker. So you first would have to find a way to build GTK with MSVC.
The easier way would be to use the recommended Toolchain x86_64-pc-windows-gnu.