I have its sibling!!!!! It's a standard kitchen cabinet tarted up with some curvy Art Noveau-ish rounded moldings on the doors to be trendy and stylish. Mine is oak, with the same moldings on the doors and bottom, same rosette at the lock, but mine has two rows of drawers (two small, one full width) between the doors. Your door pulls are not original. Mine had no pulls and no marks where a pull would have been. They may have had "push-open" catches. Mine also has old glass in it - the slightly wavery stuff with the tiny occasional stretched-out bubbles. That is NOT hand blown, it's the kind of mass-produced glass they made by pulling a sheet of glass up out of a cauldron of molten glass. Your cabinet doesn't look like oak - it could be walnut, poplar, butternut, or any of the other common wood species. Mine was identified by the seller, a knowledgeable dealer, as from 1900-1910 - apparently the way the panels of the doors are rounded had a short life because of the machinery it took to make it, and because the Art Noveau trend died out. I forget what I paid for mine, but it's a well-made vintage cabinet with rather nice wood. Here is a link that might be useful:

The feet are hideous but I agree with Wendy in that the underneath photo doesn't seem to show anything suggesting they were not original. If they are not the original feet, there must have been some other feet in place as the centre panel has a curved end which extends lower than the body of the cabinet, and under either door are decorative bits which also extend below the body of the cabinet.

That would be a French Vitrine (curio cabinet) with a Vernis Martin finish.. kind of that golden "frosty" type finish. The legs are classic. Date wise, I would guess around 1900-1915, but could be a decade or so older. They CAN be quite valuable... 3-10,000 for a decent piece, however, the condition is pretty... well... it's rough! You're correct in not replacing the glass, especially if you still have the piece that is broken out. I can't even imagine what it would cost to replace. There are things you can do to prevent further deterioration, however, that would be only if you plan on keeping it for personal use because it WOULD diminish it's value. Insure it? That's a judgement call. In good condition, insuring it for 3-5,000 would be fair.

It's "furniture store furniture" not likely to find any maker's name. As has been said, 1930's. Looks like mahogany...nice useful piece. Worth? What someone will pay...perhaps $150....$180?