That looks fine.  I've never played an all-koa mandolin, Martin or otherwise.  I assume it's more mellow?

Was it set up to your satisfaction, or did it need to be tweaked?

Very nice. Looks like a good start to the new year.

I've had a couple of regular Martin A mandolins in the past. Would need to play they side by side to make a good comparison, but based on memory, I would say that the AK is a bit brighter than the spruce topped version. It might not fit into a bluegrass band, but it's a really fun and historic instrument for around the house and more folky music. Strums super well and surprisingly loud.

Those Martin mandolins are sweet. Great for lots of kinds of music and everyone thinks of bluegrass but that one would be good for so much more.

There are a few things that I really like about these old Martin flat back/bent top mandolins.
- really loud
- sweet tone; oval hole mandolins are know for this, but this has an even rounder tone than carved oval holes. It sounds more like a bowl back than a Gibson A. I guess that should not be surprising given that the top of a Martin A is essentially the same as the top on a bowl back mandolin.
- seriously resonates; I don't know if it's the big body, bracing or what, but it's kind of like a good Martin guitar.
- amazingly sturdy. There is really nothing to adjust here (no truss rod or bridge adjustment). Still, it is 89 years old and set up remains perfect.
- one of the few vintage instruments that have gone down in price in recent years. They are not popular right now, which is good if you like vintage Martins.

The "Two Friends Quadrille" that Brettzke posted a couple of days ago is a nice example of what these Martin A models sound like. Very sweet tone. More like a really loud bowlback than like a Gibson A.

Cool Jim! Do you remember what the back was like on the Martin? If the bowl was rosewood with 18 ribs, it was an 0 (726 made between 1905 and 1925). Rosewood with 9 ribs was a 00 (1258 made between 1907 and 1925). Mahogany back would be a 000 (462 made between 1909 and 1917).

Good trade (oops, forgot that this is a mandolin forum for a second).