Could you please provide some details on how you used your mingw-static toolchain to build OpenBLAS, numpy & scipy? I would like to replicate but apparently the default Makefile in the openblas projects expects unix commands such as `uname` and `perl` that are not part of your archive. Did you compile those utilities from source or did you use another distribution of mingw with additional tools such as MSYS?
For numpy and scipy, besides applying your patches, did you configure anything in site.cfg? I understand that you put the libopenblas.dll in the numpy/core folder but where do you put the BLAS / LAPACK header files?
I would like to help automating that build in some CI environment (with either Windows or Linux + wine) but I am affraid that I am not familiar enough with the windows build of numpy & scipy to get it working all by myself.