The meter pictured by the OP, mounts on the hot shoe but, of course, there is no integration with the camera's exposure control system. In its day the accessory shoe was strictly a mounting convenience and usually did not even accommodate flash synchronization. A meter in that location will not necessarily sample light from the right place on a subject or scene.

The Voigtlander meter is cute and most likely somewhat accurate if handheld and used properly.

I can't see any real practical use for a reflected light meter in that mounting configuration. The recommended technique of using a reflected light meter is to read off an 18% gray card, or some other substitute middle tonal zone in the subject or scene. If you are going to invest in a handheld meter there are many reflected light, incident light, spot meter types and combinations whereby you can select the place where you are going to sample the light, independent form the camera in a more convenient way. An incident light reading is made from the subject position with the light collector aimed toward the camera. In all cases, it is more practical to be able to position the meter, place it at the right distance and position for a reflected reading or aim it correctly for an incident light reading. Handheld spot meters are always separate for the camera.

Currently made meters usually have digital readouts as opposed to analog meter movements were inaccuracies in needle defection can be problematic as well a viewing parallax.

Check out the Sekonic line on the new market or a good Minolta model on the used market.

When the Leica meter crapped out on my Leica M4, I replaced it with the Voigtlander VC meter, which I found to be more or less accurate but the F-stop and shutter speed dials had very weak detents, making them prone to movement. In the end it was a pain to use. As a possible alternative, I would suggest a light meter app for you phone. I happen to use MyLightMeter, which is inexpensive, very easy to use and fairly accurate when measured against my camera meters, but there are others if you're interested.

In my beginning years (high school) I bought a used DeJur light meter for a few dollars. I then shot a lot of Kodachrome II (ASA25) but an entire vacation was returned maybe 1-2 stops OE. Wasn't happy so I later bought my first SLR--a Nikkorex F (Mamiya under a different name) and later added a strange meter you could attach to the top via a 90 degree shoe. Then my exposures were about 1/2 to 1 stop under--so I was getting better! As I attended photo school, we generally purchased Sekonic incident meters and most everything for the last 50 years have been right on. However I've added meters from Gossen, Soligar, Vivitar, in-body Nikons, a couple of later Sekonics, but I did shed several tears when I sold the original $26. Sekonic. Now I'm spoiled on my Sekonic with built-in radio control, but I'm sure that's even dated by several years! I also bought a used Kodak Instamatic 500 that I wanted way-back. It had a Schneider lens, Gossen meter, Compur shutter and retracting lens. The meter died, so I inquired at the time, but Kodak's ability to repair the meter lapsed some months earlier--oh well it is still a fine shelf camera!