I have the C35 automatic. Light seals are shot (I use lots of electrical tape) I use an LR44 sized Wein cell, and just pull the sealing tape off to expose 1 hole and cut off the rest f the pull tab handle; they seem to last for months reliably with the lens cap on for me with only one hole exposed. I use a small ball of aluminum foil to keep the nominally too skinny battery pressed into the battery chamber.
No manual override, but I do fiddle the asa setting to adjust for the slightly different battery voltage prior to finding a deal on wein cells.
Nice sharp lens, small. I load mine with e-6 and carry it around with me in the bag I use to carry stuff between my home and my office, to caputre images as I come across them in everyday life.
No way to turn shutter trigger off unless you get in the habit of winding the film on just before you take the shot. I regrettably instinctively wind the film on just after I have exposed it, so I end up with some blank frames fron the shutter being bumped as it bounces around in my bag.
Flashmatic exposure works fine for direct flash, but you need to find a small flash with a relatively puny guide number. There is no capacity to bounce flash, or use the auto cell in the flash as far as I have been able to figure out.