Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
If not available as a reproduction or daft price I would try to find a used one. I would not be keen on repairing until all other avenue's are exhausted.
Didn't realize it was for a UK G5 ... Could it be that the 74 USA model has a K4 style yoke.
This would work out to about £160- to your door.https://www.ebay.co.uk/itm/1974-Honda-CB360-FRONT-FORKS-CLAMP-TRIPLE-TREE-STEM-A2-3674/154189253583?hash=item23e6654bcf:g:O3sAAOSwRtlfrAYE