I agree. It's quite messy. That's why I use the C# swig bindings instead and if I had to use Excel as a UI, I'd build my own plugins in C# rather than use the ones they provide - in a similar fashion as you've done with Python.
Anyways, I've uploaded an x86 version:
PM> Install-Package NQuantLib (https://www.nuget.org/packages/NQuantLib)