Hopefully I'm posting some solos you don't already have.
Trumpet: Summer Suite - Bartholomew. Movement 1, "Popsicle Rocket Sunrise" just became my new go-to for a first time Class 1 solo. Andante and Allegro - Ropartz Petite Piece Concertante - Balay All 'Antica - Goeyens Suite - Gibbons/Cruft (play the first 3 mvts.)
Horn: Inspiriation - Wendt. The entire solo is playable, but you only have to either play from the beginning to letter E, or from letter E to the end. Rondo in Bb - Cooke Pavane pour une Infante defunte - Ravel (Solos for the Horn Player) Reveries - Glazounow (Solos for the Horn Player) Concerto No. 1 - Mozart (play first or last mvt.)
Tenor Trombone: Concert Rondo - Mozart/Ernst Sonata No. 6 - Galliard Sonata No. 1 - Galliard Petite Piece Concertante - Balay/Voxman (Concert and Contest Collection for Baritone)
Bass Trombone: Trigger Treat - Hoffman Sonata - McCarty (play mvts. 1 & 2) Concertino Basso - Lieb I believe you can still use any class 1 Tuba solo as well.
Euphonium: Largo and Allegro - Marcello/Merriman Andante and Allegro - Ropartz Sonata No. 6 - Galliard Sonata No. 1 - Galliard Petite Piece Concertante - Balay/Voxman (Concert and Contest Collection for Baritone)
Tuba: Concertpiece No. 1 - Vaughan Variations on a theme of Judas Maccabeus - Beethoven/Bell Air and Bourree - Bach/Bell Concertpiece - Painpare' Sonata No. 1 - Marcello/Little Ricercar - Gabrielli/Morris
Call JW Pepper. They have data that tracks the number of purchases based upon the PML - they can tell you which solos, ensembles, and full band selections are performed the most frequently.