I picked up a Zephyr tenor and was wondering what it is worth? It is S/N 305XXX. It has the double socket neck but only one strap ring (Series IV?) . It has the traingle brace. It plays pretty well on older pads and has the origonal case. I already have two nice tenors (both have modern keyowrk) and think I'm going to sell this one. Any thoughts on its value would be appreciated.