I could be wrong, but I'm not so sure that drum isn't supposed to have a step. I just checked on a tf drum on my shelf and it had a huge step, but I don't remember exactly what it's out of. Maybe an A500.
On the 904......from the front of the drum. It steps up
On the 999.....it steps down. It not being burned has me thinking it’s original but I go back and forth.
If .050 wore that thing down.
It wouldn’t be smooth if the reverse band wore it down. It would be grooved and have hot spots if it was naturally worn down that much.
The converter is going to be rebuilt by a company up the road.