I'll stand corrected, but...
The 1983 495 MX models had conventional forks with disc brakes.
In 1984 they had USD WP forks with drum brakes. (The disc was that bad)
For 1985 they went to USD WP with a disc brake set up.
The white protectors shown in your pic are still avaliable from KTM, but not the left side drum brake guide, you would have to settle for a disc version, the one without the cable guide.
You can also still get the protectors in yellow (a Husaberg part) and you may be able to get them as a genuine Acerbis part as well given that the forks were used on many bike from Europe and the ATK from USA, but i have never tried that route.