What kind of cabinet is this?

This belonged to my wife's gt-grandmother (married in Muskegon Michigan in 1884, passed away 1929). It has 3 removable shelves inside, no label anywhere, and a stenciled mfg mark on the back "1687 3/4". Wife's mom used it as a china cabinet. It's 58" tall, 41" wide and 15" deep. Here's the front view, the trim and the hardware. Can anyone give an approx date and what it is? Thanks!

 

We need to see the inside

 

Does it have shelves inside?
Looks like a linen cabinet to me.

 

I was thinking maybe a music cabinet.

 

Likewise. But we need to see with them doors open and the three removable shelves.

 

Here's the inside. In the 'far' shot, that's a wayward post-it in the top area (not a mfg label) and a lonely film negative at the bottom. The close shot is to display the shelves. The shelves are held in place by small brass hardware fixed to the walls, but the shelves lift right out.

 

Circa 1920. Maybe a linen press, though not a terribly common piece for that time frame. Might have just been considered a general dining room storage piece for silver, linens, etc.

 

Since each door has a lock (same key), does that make a difference?

 

Very common cupboard in my neck of the woods, sometimes called a "bargueno" meant for everyday crockery and glassware (so maybe in line with the 1920s Spanish Colonial Revival over there).
The lock is nothing special, simply kept the door shut. What could make it a little special is the ebony, or ebonized wood, inlay.