While the P-3C has been retired from US Navy front-line service, two squadrons of Orions reman in service with the USN Reserve, VP-62 at Jacksonville and VP-69 at Whidbey Island. VP-62 operate seven P-3C one of which is 161121.
And the reference to "amarcexperience.com" is just plain wrong - a 2-second search of their database shows 161121 is not at Davis Monthan.