I just said that. Yeah, he definitely had a late peak. . .I'll try to see who else is like that (among part-time players.) Late in his career the Cardinals had him and Gene Oliver, who was kind of the same guy except right-handed. They could both hit.
Sawatski's late-career improvement is highly unusual, if not a record. Sawatski's career OPS was .610 through age 30, and .809 after age 30. There are 1,669 players in history who had at least 500 plate appearances by age 30 and at least 500 after age 30, and who were not active in 2015. On average their OPS was 24 points lower after age 30 than before, and 1,092 of the 1,669 had lower career OPS after age 30 than through age 30; the other 577 were higher.
Sawatski's 199-point improvement in OPS after age 30 is the fourth-highest in the group, behind three steroid-era players (Mark McGwire, Barry Bonds and Ken Caminiti.) 4th is Sawatski, and then there are three guys who were about 30 years old at the start of the lively ball era (Cy Williams, George Harper and Ken Williams), so that their pre-30 production is in the dead ball era, but their post-30 production is in the lively ball era. There is really no other Carl Sawatski in history, although there are guys who are vaguely similar like Jim Hickman, Tom Prince, Hank Gowdy, Hank Severeid and Charlie Lau.