On the other hand, the pronunciation in van Gogh’s local dialect would have been quite different from the standard Dutch pronunciation (with a “hard g”).

Then again, assuming this name refers to the town of Goch, the locals there (just across the border in modern-day Germany) pronounce it differently from both of these, which would likely be different from the way it was pronounced in van Gogh’s time (some Low Saxon or Low Franconian dialect, I’m guessing).

However, none of these pronunciations are anything like the absurd American or British English variations.