Hi, newbie to disc brakes. Just got a 2003 bike with Shimano XTR discs (BR-M965). The front wheel calipers are not centered and rub very slightly on the inside caliper. It's consistently off-center through the entire rotation. The rotor seems straight and tight and the wheel is true. These brakes have the "post" mounting thing, where the mounting bolts are perpendicular to the rotor (see pictures). So it doesn't seem possible to adjust in/out with those bolts? I found a manual online here, but it's way over my head:

https://hollandbikeshop.com/images/SI-8CM0G-000-ENG.pdf

Any advice would be much appreciated, thanks.