Vintage Ping Anser Golf Putter w/ Bronze Head-1968-1973

Inside the slot:
Made in the USA
U.S. PAT NO. D207227
KARSTEN MFG. CORP
BOX 9006 PHOENIX ARIZONA
85020
From the zip code it is from between 1968-1973
https://forums.golfwrx.com/topic/1302824-how-to-determine-date-of-ping-putter/ 
In good condition-the shaft is loose