The front brake issue is usually a plugged fluid return hole in the master cylinder. This is a physical fix, no parts needed.
OF course you'll want to bleed the system, clean the caliper (could be stuck as well. A tap or two with a rubber mallet will work wonders till you can fix it for sure) and the master cylinder.
Now that these bikes are approaching 40+ years old, low mileage is no guarantee of an easy restore. Age does it dirty work as well on the rubber bits especially. Inside the motor and out. Cables, tires, hoses, plastic (side covers get real brittle) etc.
Still a fulfilling endeavor though.