Looks like DDD. It’s also present in IGWT. I don’t remember and rpms for 1980 WQs. That coin appears heavily pitted probably from environmental damage. JMHO
Looks like the whole surface of the coin has been damaged on both sides, blurring the features. Could be a die chip in the date as stated above.
I'm on @paddyman98's side on this one. Appears to me to just be a filled MM plus circulation wear and tear.