Could also be the seals in the caliper doing that and causing that same feeling, If the caliper seals are sticking I would have thought that they would hinder the front wheel from spinning, apply the brakes a few times stationary letting the lever out slowly and try spinning the front wheel, if it spins fine then your guess is probably a good one.
Might be worth checking the brake lever pivot pin to make sure that is free and the pin hole in the handle bar mount is not worn oval as that can cause issues as well.
But as you say it is very low mileage and if there is a lot of rust around the bleed screw then the caliper piston seals are worth checking, so its worth a check to see if they are causing the judder. As the bike is stationary it is not a rolling issue for example warped discs, or a buckled wheel, both of which can cause discs to snag.
good luck.