The Conn 76A Connquest has a #2½ Bore (0.485′). In 1961 the 76A apparently replaced the 77A Connquest, which has a #1 Bore (0.438′). The 76A was produced through at least 1971. One of the ‘professional’ features of the 76A Connquest are the top spring valves.
What Conn said in 1963:
Designed with the student in mind, easier to play, assures faster progress right from the start. Features include: nickel-silver mouthpipe, added guards for protection of rams-horn knuckle and 2nd valve slide, nickel outer slide and brass inner slide on main tuning slide, separate clean-out slides on bell and mouthpipe, three sets of valve casing braces (instead of usual two) for added rigidity, short model (less than 14 inches long), special-design third valve ring.
What Conn said in 1966:
Short cornet designed especially for the student. Easier to play and highly responsive. Seperate clean-out slides on bell and mouthpipe, third valve slide throw ring, three sets of valve casing braces. Brass bell. Length: 15′. Bell 4¾’.