That appears to be a Bulldog Electric Pushmatic circuit breaker panel. The bus bars for the breakers in that panel are flat, straight, and run vertical, which means all the breakers on one vertical row are connected on one straight bar. The double pole breakers (the one at the top and another one in the pic that is the sixth breaker down from the top) run horizontal. I had to get my breakers for those panels from EBay. Those breakers are screwed into the bus bar, so for safety reason, you must turn off the power at the main breaker when removing and installing a circuit breaker.