Looking at your SDK SQLCompareReport project, it references RedGate.SQL.Shared, but in SQL Compare8 that DLL no longer exists.
I thought it might be:
C:\\Program Files (x86)\\Red Gate\\SQL Compare 8\\RedGate.Shared.SQL.dll
But the program is still missing references:
The type or namespace name 'DiffHelper' could not be found (are you missing a using directive or an assembly reference?)