Yup - I also recently saw Corey on Barney Miller as an Amish man.
He also did another Barney as an elderly ex-con who commits a crime because he can't cope with the outside world.
Barney's in our dinnertime rotation of half hour shows to watch while eating. We watch one whole disk, one ep a night, then rotate to another show. It's a couple of months between Barney Miller disks, but even at that my wife and I find ourselves saying saying "HIM again!" (or her) all the time.
I have so many favorite BARNEYS, and so many favorite 'him/her again' people, it shad to choose the best. Always a soft spot for Phil Leeds - one was on Antenna the other night where this plain looking lady had gotten charmed by, and then accosted by a suave, good looking 'photographer' , and when they find him and bring him in it's - Phil Leeds. Dietrich, bless him, just goes, "NO!".