Hello all!
I recently landed a small editing job, but I think I need a little help. Before I begin, I know I will probably run across other small confusions in the future. Should I make a new forum for each problem, or can I simply ask new questions as a reply?

Here are the problem sentences:

"What do you mean... had?" I asked.
"I mean... had. They came, they stayed and then they left."

I made the first quotation have a full ellipsis with all the spaces as I'm assuming it's a sort of 'trail off' or slow and uncertain pause. I also put "had" in single quotations. But I don't think the reply sentence requires that. I understand it as being a definite pause. So I am curious as to whether I should in fact make it an ellipsis ("I mean . . . had."), or remove the periods. If I remove them, should I just throw in more single quotes ("I mean 'had.'") or should I use an em dash ("I mean—had.")? Am I completely wrong and in need of something else?

Thanks for all of your help!