I used Honda VF500F forks on my 78 Bonneville, I wanted somewhat less trail for quicker steering, Honda yokes wrked. And I wanted a slightly steeper fork rake, 18 inch wheel did that. Bonus was speedo drive from RD250 front wheel, reliable Japanese speedo. I used single disc.
That for and Ohlins shockers transformed the bike, embarassed a couple first year Ducati Monster owners soon as I got it on the street.
Of course I have reduced the Triumph's value greatly, but I don't care. No restorer would want a post 1970 Triumph anyway, we used to say.