About 6 months ago, I queried a well-established agent at a large agency. He liked my story and asked for more manuscripts, but passed after reading the rest. Admittedly, I committed that newbie blunder of submitting before I was really ready. I did not have a strong stable of pieces to back up my first.
Now, though, I do, and I would like to re-query him. Here's my confusion: I never actually corresponded with him directly, but rather with a more junior agent who acted as an intermediary. When I re-query, should I address my query to them both? The truth is that I would be thrilled to be represented by either of them.
Also, on a more minor point, after corresponding with the more junior agent a couple of times, we were using first names rather than the more formal Ms. Xyz. When I re-query, should I revert to the more formal standard?
Were you invited to re-query when you had more work to show? If not, don't assume they are looking for another query.
Also, if you never corresponded directly with Senior, my guess is he hasn't seen your work at all. It was the junior agent. Absent the phrase "Senior Agent has asked me to" you should assume the person reading and assessing your work is the person signing the email.
Somewhat like the QofE has staff to answer her mail, Senior Agents have minions whose job is to scout around for good stuff. If it works into something good, Senior Agent might swoop in, but as you say, you didn't have your best work then, so Senior didn't swoop.
And of course, it's entirely possible Junior is starting to build his/her own list under the supervision of Senior. That's exactly how my assistants got their start.
And thus, any future queries should be directed to Junior. And call her/him what you had been. It's weird to revert to formality if you're on a first name basis.