Wow, I got it today, finally. Well, to my initial disappointment......the body is...hmmm..not in good shape. Other than the lens, the apreture, and shutter.....everything else is...bad. The leather was intact pretty well. Hehehehe

I got so upset with this purchase that I was thinking returning it to the seller. I then asked myself I couldn't do better paying only $80 shipped for the Yashica Mat. I went out and did some errands and came back and began to thoroughly check the body to see if I can fix it. I suspect that I should be able to fix everything else other than the lens and shutter mechanism.
First, the body bottom corner, inside the film chamber, is missing the corner. A big chip. Hehehehe.... It was obviously dropped at some point in its life with the film door open.
Second, the crank was mad stiff and the film counter wasn't moving.
Third, there are some marks inside the lens element, the taking lens. Obviously, oil marking being dried up through the years.
Fourth, dust and dirt on the mirror and the focusing screen.
Fifth, foam needs to be replaced.
For the past 4 hours, I managed to super glue a piece of a metro card cut into the shape matching the missing corner. So that light leak isn't possible at one of the corner. Once you close the film door, you won't notice it. I used my lens spanner and to remove the front and rear elements of the taking lens. It turned out the lens is in good shape, surprisingly. Only the front element has some tinny scratches. That won't affect the image quality as long as I am not shooting at a light source. I ripped out the leather on the crank side and removed the cover. Surprisingly, it was very clean inside. I didn't remove anything inside and just applied some dry lube and some WD40 by the crank mechanism. Inside didn't need cleaning at all. Right now, the crank action is very smooth. Fixed the film counter too. Next, I removed the foam on the film door and to put some window sealing foam in it instead. Tomorrow, I will test a roll to see if all would go well.....
Now, if only I could get my hands on a sparkling clean front element without any marking. Will probably need to get some new leather and maybe different color too...