When was the 74HC595 designed?
The Fourth Edition, 1980, of TI's "The TTL Data Book for Design Engineers" (the TTL reference at the time!) doesn't list the 595.
I found references to the original TTL 74595 (pre-LS) on the 'Net, though. Probably will be from well before 1980, the Data Book already contains many LS-TTL ICs. It's old.  

Note:
I've advised here before against using the 74HC595 to drive LEDS: 8 LEDs @ 20mA/LED exceeds the maximum device current of 70mA. The original 74595 may not have been used to drive LEDs, they weren't that common mid-70s. I remember seeing 7-segment displays in a Radio Shack (Tandy in Belgium) catalog at the time, which used electric filaments instead of LEDs. That was already in the same housing the LED displays use, not a tube.