Don Christensen

Hard to tell from the pictures, but it looks to me like a mid to late 60's model. There's no micro-tuner on the tuning slide, the mouthpiece receiver is smooth and somewhat funnel shaped and 3rd valve slide has a spot for a finger ring. I have a master cornet with similar features from the same era, but it has the micro tuner adjuster. I would guess that this is an East lake built cornet probably built around 1968 or so.

Edit: maybe the micro-tuner is there after all. It's really hard to tell from the crappy pictures. If it is, then the horn is probably made in Cleveland and could have been made between 1953-1965. Most of the early 50's horns that I've seen have a stepped receiver on them though, so I'm leaning towards it being a 60's horn.