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1 inch or 1 1/8th? Is a headset spacer mount not possible? GoPro mount type or others are available.
(loads of other possibilities if you don't want the light on your bars - incl. using rack mounts, axle ends, brake holes, etc. - maybe look in the hacks and bodges thread for some good ones)
Jurek probably is only a decade out though - I can't remember anything past the early/mid 1980s with them.
Edit: I initially thought you were trying to fix an old lamp to a new bike.
When did lamp brackets on forks stop being a thing ?