I've been reading through sections of the 1971 NEC that I acquired, and have actually just reached 240 on overcurrent protection.
The current NEC's 240.80 thru 240.82 seem to have all been covered under 240-25 in 1971.
240-25(c) says that breakers must indicate whether they are in the open or closed position, but I can't see anything else about orientation.