This is a great classic camera which is fun to use, but it has definitely been loved & used. When pricing this camera, we have taken into consideration that it is working and has been film tested, but that the exterior is worn and the light meter is missing.
First, The Good News--
This is a great working camera which has been used and enjoyed.
It was recently filmed tested and produces beautiful pictures.
Now For The Reasons We Aren't Asking More--
The Exterior is Worn with chipped paint and a misaligned top around the "Y".
The Original Light Meter is missing. It would have been mounted on the front of the camera above the twin lens.
And the Focusing Screen has dimmed over the years, but does not affect the usability or image quality of the prints.
While we have tried to describe the camera as accurately as possible, in addition to provided multiple photographs, since we were limited by ebay to 12 photos, so we may not have a picture of every imperfections, if you have additional questions or concerns, please send us a message.
Due to its age and fragility of this camera, we are selling it in "AS-IS" condition. Serial Number Taking Lens 264752
The Information Provided Below Is Courtesy of Fadom on Camerapedia:
The Yashica-Mat LM was introduced in 1958. "LM" stands for Light Meter, referring to the uncoupled selenium cell exposure meter in front of the viewfinder. It's an all-mechanical camera; even the light meter doesn't need a battery. The Yashica-Mat LM is a solidly made, easy-to-use camera.
Features 
It has a Copal central shutter with speeds from 1s to 1/500 and B. It offers flash sync at all speeds. The taking lens is a 3,5 Yashinon, an 80 mm four-element lens said to be of the Tessar design. It can be stopped down to F/22. The viewing lens is a 3,2 Yashinon. It accepts bay I filters. Shutter speeds and diaphragm are set by two wheels on the front plate, the values set are shown in a window above the viewing lens. Looking onto the ground glass in the waist-level finder, both values and light meter indications are visible.
Focusing is done by a focusing wheel on the left of the camera. It has a distance scale surrounded by a depth of field scale engraved in the body.
There is a small window in which you can set the ISO value of the film you use and scales for LV, shutter speeds and diaphragms.
The body is all-metal, covered by black leather. It is quite a heavy
camera, about 1.2 Kg. Film transport and cocking the shutter is done by a
crank. Winding makes a rattling noise.