My sister would know the exact connection. He's on my mother's side, but that is not her maiden name, and he was about grandfather-level older than I am, so probably he was a cousin of my mother's father--that would be my guess. She, and consequently we, referred to him as "cousin," so that seems right. So yeah, I'm going to go with first cousin twice removed. I'll be helping out my sister early next week, and I can correct after that if I'm wrong.

I'm amazed that you can remember things like that I've said this and then come back and find the entry!