“Pinball” coin doors are the doors that typically appear on pinball machines. Their size is determined by the typical shape of a pinball machine. They have to be wide enough to accommodate three coin slots and feed into a flat coin box.
Pinball doors were frequent on video games (all Williams, all Midway, early Atari). In the early days of video, they were the only doors available, but after a few years many video games went to an over/under double-door.
Inserts, buttons, and internal brackets tend to be shared with similar parts from the same OEM. That is, you can scrounge Coinco parts from an over/under door to fix your pinball-style door, provided they’re all Coinco.
I believe that these doors come in some subtly different sizes, so you can’t swap out the whole door without making sure it will fit.