I was gifted two very clean SRT 101 cameras and assorted lenses. Mechanically, these guys are good to go. The meters aren’t really necessary, but I like to make at least some effort to bring them back to spec. The cameras were a little dusty with dead batteries. I dusted them off and plugged in my 675 hearing aid batteries with brass adapter. One of the meters works when I apply pressure to the power disk, the other nuttin. The battery compartments are clean, but I am guessing there may be some corrosion under the hood. Any suggestions or anything that I should look for before I pop the hood on these little tanks?