What is the value of a conn trumpet serial number 705401?

The value of a Conn Trumpet with serial number 705401 can vary based on factors such as its condition, model, and market demand. Generally, Conn trumpets from the early to mid-20th century can range from a few hundred to over a thousand dollars. To determine a more accurate value, it would be advisable to consult a music shop or an online marketplace specializing in brass instruments. Additionally, checking recent sales of similar models can provide a better estimate.