I'd venture a guess he didn't do anything. The headset is clearly not original. It's almost certainly a standard ISO 1" headset, but those are typically close enough to fit if you're not too OCD. Sometimes you'd have to reface the fork crown, but obviously this is a replacement fork so that wouldn't be needed, and I didn't think before typing.
If you were to find an old french fork, you would need a new headset, as the threads are different. Also, that original ATAX stem is probably a pretty loose fit, as frenchie stems are 22.0 vs 22.2 mm.