it is after 1960 due to it having the newer logo but probably still old. I've nver seen a vintage T5 before even though the 4 6 8 13W tubes have been around as long as T8s and T12s. I've rarely seen a T5 BLB period!
I have a F4T5 BLB too that came with a cheapo battery powered black light from WalMart. The endcaps aren't installed right so when one end of the lamp is properly inserted the other end isn't. it's still a cool lamp even though it's a no-name chinese lamp.
I find eBay, and occasionally hardware stores and Restore usually have vintage T5s.