Other people's experience may be different, but in my experience, it is rare for a 1970’s era micro-computer schematic to completely match a board, as it was actually manufactured. Component differences and wiring differences are often found, even when comparing schematics that were drawn for a specific version board, to that same version board. You may want to determine how it came from the factory, in order to determine the best course of action for you. Regards, Mike W.