I finally got around to performing the tune up on new-to-me '89 760T. When I removed the turbo inlet hose to replace the air filter I found that the screen on the output side of the AMM was pushed into the AMM body, torn, and frayed. I replaced the screen with one from a spare I had on the shelf. I am wondering if this is just from mis-handeling the last time someone replaced the filter or if there is some other cause. i.e. backfire through the throttle body? Is this anything to worry about?

Side note: The Bosch distributor cap I took off had a label stating that it was a VOLVO Remanufactured Part. I didn't know VOLVO remanufactured any parts. Also I was sort of surprised that this was not the original distributor since the car had 106,000 miles when I bought it. The Bougicord ignition wires that I removed were dated 07-97.

Thanks in advance.
Dan