COM Type Library imported to .NET not fully functional

Hello

This is my first MSDN question ever :-)

I have an old COM type library file (.tlb) containing various structs, interfaces and also method declarations for calling methods in ole32.dll, oleaut32.dll and kernel32.dll.

The .tlb file is working just fine from VB6.

I have imported the COM type library (.tlb file) as a .NET assembly as described here:

https://msdn.microsoft.com/en-us/library/xwzy44e4(v=vs.110).aspx

The importing part is ok but when examining the .NET assembly none of the declared methods to ole32.dll, oleaut32.dll and kernel32.dll are accessible/visible. When examining the new .NET assembly in IL DASM all of the DLL nodes in the treeview are just showing ".class public abstract auto ansi sealed".

Im a bit lost. 

Any ideas...?

Edit:
I've imported the .tlb file directly into Visual Studio, I've used the Tlbimp utility and I've also tried the TypeLibConverter class. All of them with the same result.