Lyon & Healy was a merchandiser that stencilled their brand on horns made by Couturiere.  Lyon & Healy horns are quite common and don't have a lot of market value.  The value would be lower if it is a C-Melody.  A tenor measures around 30 inches from the neck receiver to the bottom of the bow, a C-Melody closer to 25.  

This horn lacks a front F key, which marks the keywork as antiquated.

The finish on the neck looks very different from that on the rest of the horn, which suggests to me that it is probably not be the original neck or it has been damaged and repaired.  It should be play tested to see if there are any problems with intonation or response as a result.