Minolta Hi-Matic. I bought this camera without knowing much, a film was still inside (but did notice too lately, so no found film images) and looked externally in good working order.
The camera suffered from acid leakage from the battery compartment, the range finder was completely blocked and also opaque, the aperture blades always closed.
First I removed the top cover of the camera and then the whole range finder assembly (it comes easily of as a whole). The RF has a top cover which is glued on, I removed it. I cleaned it with avgas and then alcohol. I did not remove the mirrors, but cleaned from above, so it is not perfect: however it is acceptable and the mechanism is free again.
Much harder was trying to revitalize the Light Meter and the Aperture.
At the bottom, the acid leaked and completely ruined the wires, I removed everything and with great pain reconstructed the battery holder.
I had to tackle the lens. I removed the front cover. It contains the cell, but also a mechanism with a ring that rotating regulates the light on the sensor coupled with the shutter speed.
The Sensor element (sealed CdS) has a small PCB and the wires were completely oxydated and corroded. I cannot tell if this is age damage or caused by vapours of the battery going through the lens.
Harder was to get the Aperture. The front part of the lens can be unscrewed, it was very tight and had to use Pliers! I guess the metal stuck a little. Then I could not see how to proceed further and wished not to tackle the lens from the back. No oil was to be seen, but I cleaned and cleaned again with avgas and by miracle this started to move reliable. Fine!
And, then everything reassembled, the compact camera with a very nice 40mm 1.7 lens is ready to go again.