Was the man a long-lost uncle, or was he only somebody who had sat opposite him regularly in a railway train?

Perhaps he needs to find a long-lost rich uncle.

Often he presents himself to his relatives as a long-lost uncle, or simply is allowed to work close by to keep an eye on them.

"Your long-lost uncle who was, ostensibly, lost in the Swiss Alps fifty-seven years ago."

Janina received a call from the tracing service caseworker and was soon talking to her long-lost uncle and aunt.

Charles doesn't recognize his long-lost uncle.

Joseph, like Charles, does not recognize his long-lost uncle.

The guys didn't seem to notice and greeted their Russian driver like a long-lost uncle.

You've been here three days and you've got the most important women in my life treating you like a long-lost uncle.

'Yes, you didn't know I was their long-lost uncle, did you?'