It may only be on a postcard, but I would love one like this, even a new one.
It states:

The Mysterious Clock
The Crystal Bar
Virginia City Nevada.

Sheila,
Looks nice. I have never seen one, but it looks like you could make one yourself. That way you could get a frame to match the rest of your furniture. Get a glass place to cut a mirror and drill it for the clock. I would use a quartz movement. Just stick the numbers to the mirror, make the numbers and hands out of something that matches the one in the picture.

Andy

Looks like it may be one of those mystery clocks that runs off of watch movements located in the counterbalance of each of the hands.

Sheila,

Here is a detailed view of the hands of that clock. It looks to me like the hands are counterweighted, and that is what the short cylinders at the end of each hand are. You can see their reflection in the mirror behind them, with the top (minute hand) counterweight's reflection being farther from it than the bottom (hour hand) counterweight's reflection is from it. It looks to me like the mechanism is indeed behind the mirror, so a hole must be drilled through it. It is an interesting example of a mystery clock!

-Kent