www.ebay.com/itm/275649427846?
Printable View
It is beautiful.
I'm guessing it's not quite as large as Joni Mitchell's 1915 K-4 mandocello that she bought from Stanly Jay (Mandolin Brothers, 1976) and wrote "Song for Sharon" on (Hejira album, Side 2 Track 1).
Looks like 20 inch scale length.
1 & 1/4 inch fretboard width at nut.
Year 2018
Price (so far) $4,400.00 plus $50 shipping plus tax.
Beautiful and I'll bet it sounds impressive.
Mandocello = 24 & 3/4 inch scale length (long as some guitars).
Octave Mandolin = 20 inch scale length.
Here is a (not so wonderful recording... Hisssss) of a Weber Yellowstone A Octave Mandolin in action (Youtube) https://youtu.be/x9qUnao2Wpw