This does not look like a good deal.  For starters, I suspect that it is a c-melody and not a tenor because it has a microtuner neck.  The length of a tenor from the top of the body tube to the bottom of the bow should be close to 30 inches (about 75 cm).  If it's closer to 25 inches, it is a c-melody.  A c-melody in need of an overhaul isn't worth very much money.  

That horn looks like a product of the Elkhart Band Instrument Company, which was a joint venture of Conn and Buescher in the mid to late 1920s.  Those horns commonly had a combination of Conn and Buescher features.  Its Conn-like features are the rolled toneholes and the microtuner neck.  The keyguards, LH cluster, and neck and bow reinforcements are Buescher-like features.  The Elkhart Company produced "stencil" horns that were sold under the brands of merchandisers as budget horns.  This one appears to have been made as a "deluxe" stencil because of the rolled toneholes and microtuner neck.  The finish and engraving are a little fancier than you see on most stencils too.  

The value of the horn is in all likelihood less than 500 USD in good condition.  On the plus side, the overall condition of the horn looks pretty good so repair costs might be reasonable for a horn of that value.