Steel Hardtail UNAUTHORIZED RPM 45

Here is my friend's Unauthorized RPM 45. I saw this bike for the first time in almost 2 years. He doen't ride on a bike now and lends it to me.

We used to ride together before and the bike was still at that time...

Front tire is blown...

Immediately I dismantled the bike. Almost all the parts were wasted.

Unauthorized RPM 45 is made from Chromoly steel. The area chains hit is rusty.

Many rusts are found on the frame but it doesn't seem to be so deep. I will do an antirust treatment then build a bike. Tapered head tube and 142x12mm rear end are standard for latest frames but Unauthorized RPM 45 has a headtube that fits 1 1/8 fork steerer and 135x9mm QR rear end. I don't have such components and have to buy...