Source: 6895alberto on eBay.com
This horn has 3 very obvious things that ID it as a very early Toneking Solo--thus making it quite different to the ones displayed here with the known serial #'s.
1. It has split bell keys.
2 The left pinkie cluster is what we see on older JK horns.
3. The bell engraving is different to the other Solo models in this gallery.