Did you have the DLLs in the same folder as the .exe?
<sigh> No, I had the DLL's *folder* in the same folder as the EXE.
So, for those of us who are brain dead, would it be worth putting the DLLs into zip along with the exe instead of in a separate folder? That or change the readme to "extract the contents of the DLLs folder". To me that's more clear. That said, I obviously did get this to work before though I suspect I made the same error but figured it out before making a fool of myself, unlike this time. Must be too tired.
Thanks. All better now.