Youll likely need more than just forks..... youll need a whole front end. this will include but not be limited to;
forks,
rim,
calipers (and brake lines),
upper and lower triple clamp,
stem, (the vintage is right for them to be similar, but no guarantee, the bearings are probably the same)
master cylinder,
fender and fork brace.
Then you need to know how long they are.... I swapped out the stanchion tubes from a Kat100 (41mm) and kept the lowers. The Kat tubes are about an inch longer so they poke above the triple clamp. That ok for me, I attach a set of clip ons there.
Much more than an inch shorter and youll have some steering issues.
With the 17" conversion AND 1" shorter tubes, you bike will have a very VERY vague feeling front end at 60mph.... its almost asking for a speed wobble..... ask me how I know.
YMMV
Alan