Excuse my temporary ignorance in terminology. The part Im dealing with has the set of cogs attached to a "bearing" that moves in one direction only. This "bearing" has two small divots in it, that appear to be for a special tool to fit in, for removal. All of my attempts to compensate/create/outsource this supposed tool have failed. It definitely threads into the set of cogs though. If it has not been removed since the 1970's though, I could imagine it taking some force to remove, and with such small contact points for a tool, it could be impossible.
To clarify, it skips a bit in the driving direction, resulting in a temporary loss of drive, for maybe two chain links length, then catches again, Resulting in a sketchy ride. Especially when trying to get up to speed ;/ It also only happens when in the smaller three cogs. Not sure if they are referred to as higher, or lower.
Thank you for your response dabac.