Sorry Allen, I thought you were commenting about the text you quoted referring to the EFN type.
Anyway, the message is: be careful, EFP=1,000 hr. , EFN=50 hr.
BTW, the eBay add for the "13139" lamp shows the picture of a faceted reflector lamp.
The real 13139 has a smooth reflector. Maybe the picture is just illustrative, not exactly the lamp for sale.