Yeah I have given up on making the F4i/919 fender brackets. I sold off all of my f4i parts when i switched to the RC51 front end.
Are the forks on the bike yet? The easiest way to make something is to install the F4i forks and the 919 fender using the aft bolt. Then use a piece of pipe strapping to mock up the brackets. The pipe strapping all ready has holes in it and is easy to bend by hand & trim with hand shears. Once you have a general shape that will work remove them and mark the bend lines with a sharpie, then flatten ONE of pipe strapping pieces back out ..... one will be your general template for before bending ..... the other will be the template for after the bends are complete.
Find some material to make your final brackets from & lay the pipe strapping over top to trace out your template. Don't pick up any holes yet. Next mark out your bend lines and start tweaking it in a vice or break until it starts to look close to the second templates shape.
Slide the new bracket into the slot/pocket on the underside of the fender and see how it lines up with the bottom boss on the F4i fork. Once you are happy with the fitment .... mark the top hole with the sharpie and remove and drill ..... reinstall the bracket and bolt on the top hole ..... now see what tweaks and adjustments you need to make to the bottom of the bracket to get it to line up cleanly. Once you are happy with that you can touch drill it while installed to mark the bottom hole location, then remove and finish drilling the bottom hole. Once you get one made the second one is easier.