Fork tube size is pretty much irrelevant. The clamping diameter of the fork tube and the available area to clamp plus the correct distance between fork tubes are critical. The fork brace you showed will be much less forgiving that the OE brace in the correct distance between forks.
I have seen fork braces made for a specific bike that caused stiction so just throwing a part on has a low chance of success.
Couple of suggestions .... use the OE brace and shorten the fender to give the cafe look or take the fender off the brace, clean it up and put it on continue with your flat tracker look.
I have seen fork braces made for a specific bike that caused stiction so just throwing a part on has a low chance of success.
Couple of suggestions .... use the OE brace and shorten the fender to give the cafe look or take the fender off the brace, clean it up and put it on continue with your flat tracker look.