Yes, regular passenger service, although a few were pulled out for special assignment.
Immelmann and Immelmann II come to mind as special assignment Ju-52's that were pulled out of regular passenger service.
Of course the Ju-52's can also be identified by their individual civil registration numbers painted on the sides- in this case D-AXOS.
Besides Boeckle and Immelman, other WWI aces honored on Ju-52s included OTTO BERNERT, WERNER VOSS (reg. nr D-3131), HANS LOEB (reg. nr D-ALYL), renamed "XI OLYMPIADE" in 1936 and fitted with the five coloured olympic rings in honour of the Berlin Olympics, and EMIL SCHAEFER reg. nr D-AJYR).
"IMMELMAN" was reg. nr D-2600.
Then there is of course also the impressive RED one, the Lufthansa "MANFRED VON RICHTHOVEN".
Thanks to Bengt Fredén, Stockholm for this list.
John Dell added:
The reference I used for "Otto Bernert" was the Schiffer Publishers Luftwaffe Profile Series No. 14 on the Ju 52. On page 8 there is a photo of
a group of Ju 52's at Tempelhof. In the photo along with "Otto Bernert"
(D-AHAL) are: "Rudolf Klein" (D-AHIH), "Wilhelm Siegert" (D-AMYY), "Otto von Maltzahn" (D-AMIT), "Hans Wende" (D-ADER), and "Bruno Rodschinka" (D-AVUL). All of these planes share a similar layout to the names and registration numbers as is shown on Otto Bernert". There are just some slight variations to font style. At the top of the page is a photo of "Oswald Boelcke" (D-AXOS), where his name appears in smaller type under the Lufthansa name on the nose. Other named Ju 52's mentioned in this book are: "Kurt Wintgens" (D-ALUN), "Edward Dostler" (D-ALAN) and "Fritz Pütter" (D-ANEN).
Lufthansa had several hundred Ju-52's. Not all of them had names.
I wish we had a color photo of the RICHTHOFEN plane, painted red!