Does anyone know of a way to compare two .NET assemblies to determine whether they were built from the "same" source files?

I am aware that there are some differencing utilities available, such as the plugin for Reflector, but I am not interested in viewing differences in a GUI, I just want an automated way to compare a collection of binaries to see whether they were built from the same (or equivalent) source files. I understand that multiple different source files could produce the same IL, and realise that the process would only be sensitive to differences in the IL, not the original source.

The main obstacle to just comparing the byte streams for the two assemblies is that .NET includes a field called "MVID" (Module Version Identifier) the assembly. This appears to have a different value for every compilation, so if you build the same code twice the assembly will be different.

A related question is, does anyone know how to force the MVID to be the same for each compilation? This would avoid us needing to have a comparison process that is insensitive to differences in the value of the MVID. A consistent MVID would be preferable, as this means that standard checksums could be used.

The background behind this is that a third-party company is responsible for independently reviewing and signing off our releases, prior to us being permitted to release to Production. This includes reviewing the source code. They want to independently confirm that the source code we give them matches the binaries that we earlier built, tested and currently plan to deploy. We are looking for a process that allows them to independently build the system from the source we supply them with, and the compare the checksums against the checksums for the binaries we have tested.

thanks