I’d suggest aftermarket replacement ear covers and headphone strap. Mine also flaked and left crap everywhere, but wrapping the strap and replacing the earpieces has saved my pair.

Hear covers both from maker and third parties are available on amazon for that model. It is a classic model. You should find some in other non leathery material too.

I had the same issue and I simply scraped off the fake leather with a flat piece of metal from a multi tool I have. Both on the ear cups and the inside of the head band. There's a plush material underneath that is more durable.

There are relatively cheap replacements on Amazon for about 10 dollars. I bought from a brand called Krone. They've been pretty good for the past year I've had them. Though these are all cloth so I'd imagine they last longer than leather/pleather alternatives.

I had the same issue with black flaking coming from the earcups and the headband. For the earcups I resorted to buying replacement earcups which are relatively cheap. Though it's noteworthy that these changed the feeling of the headphones. There was more room for my ears which is good, and the sound had more depth but less detail. For the headband I explored replacement options, but they all required soldering. The best solution I found was to use a toothbrush and remove all the remaining material completely. This leaves a fabric feeling to the headband which is pleasant enough. No more flaking black bits in my hair. Note I did this at least a few years ago and my new earcups have split at the top but the headphones are otherwise excellent, might just need another replacement earcup if it gets worse.