Any Hagerman Trumpet users have tube suggestions?

Yes!

Make sure you are not looking at new versions of these.
Telefunken for clear, cooler, neutral, open and detailed sound.
Mullard for warmer, smoother sound.
Amperex Bugle Boy for warm, open and detailed sound.
Sylvania and GE avoid grey plates.
RCA black plates clear and detailed but can sound pinched.
Etc. 
Talk to Kevin at upscaleaudio.com

Owned a Trumpet a few years ago; very nice amp. It’s really hard to beat Telefunken 12ax7. I mean you can, but the Teles are far more plentiful and not too expensive. I believe you can also use 12at7 (or 12ay7) in the 12au7 slots (in fact mine didn't ship with 12au7). Not really a fan of any 12au7, though I haven’t tried Teles there. I’ve always wanted to like Mullards, but in the end I just have to move on to something else. Amperex are good but I prefer Teles. I sometimes like the 5751 sub for phase splitters in amps, but have found it best to stick with the 12ax7 in phono stages.

I totally agree with avoiding Sylvania small-signal gray plates of any kind! Yuck! The earlier black plates can be good, though.

Is that a “trumpet” like in “band camp”?.....

No it's a trumpet like in jazz......