Like this one https://hoopdirt.com/topic/scan-coin-303-user-manual/ I've used Scan coin counters for years and have never opened the manual. I bought a new one a year or so ago, since they aren't made by Scan coin in Sweden anymore the quality is lacking.
Here's a link for the parts The parts for the 303 are unbelievably expensive. I might have a user manual, I look and let you know.