On the go all day...sorry this is late.
Reds:
Ben Broussard (34) -I listed him as a Red even though he was traded away before reaching the Show. I always liked him, but he never ended up as anything special.
Clyde Vollmer -Came up as a Red but had his best seasons later, mostly in Boston.
Others:
John McDonald (37) -Still hanging around despite the weak bat. His BaseballReference page sponsor says he's the last graduate of the now-defunct Providence College team to still be playing.
Hubie Brooks (45) Was drafted no less than six times before he finally signed (this was back in the day when there was a January secondary draft).
Dixie Walker -Nicknamed "The People's Cherce" in Brooklyn, where he had his best years in his 30s. When Jackie Robinson was signed, Dixie had some serious problems with the concept, at which point Brooklyn management decided they could live without him.
Charlie Pabor -19th century player. It's not listed in BaseballReference, but I believe his nickname was "The Old Woman In The Red Cap"- God knows why.