Canon cameras used to have shutter locks, separate from a switch that turned the meter on and off. Many people were confused by this arrangement; Canon eventually combined them into a power switch on the T-series and have never looked back. Mamiya 645 Pro TL has a circular switch around the shutter button on the body. The power grip also has a switch around its shutter button. I keep forgetting to turn one of them off, and I don't know which is necessary to keep the batteries from dying.

The film window in the camera back is a wonderful thing. My Canon F1 doesn't have one; I can't remember how many times I've had to remove the lens, set the shutter to bulb and fire the thing so I could peer inside just to see if it was loaded, nevermind with what. I was quite surprised last year when I picked up my Contax AX wanting to see what film was loaded and discovered it had no window! It also had no memo holder. Fortunately I happen to have a few of the last Hama memo holders floating around somewhere and was able to stick one on.

Ya know Stone, if you want time lapse, several cameras that came out in the 1990s also have intervalometers available. Good luck finding them, of course! There are also remote switches with timers built in, available on ebay, for those really long exposures. I considered that such a good idea that I bought a few a couple of years ago. They are still in their boxes, of course.