Hi
About the non matching of Graf's collar patches and shoulder straps :
I suppose the photo was taken just after Graf's promotion to Hauptmann d.R. and I believe that this latter promotion was made "on the spot" (note he is unshaved, with a moustache).
As it far easier to upgrade a shoulder strap by adding one pips than doing the same thing with a LW collar tabs (try to add a bullion seagull

), straps were updated and not the tabs.
Remember that Graf was awarded in less than 9 months the KC, the OL, the Swords and the Diamonds while in the same time he rose "only" from Lt. d.R. to Oblt. d.R. !
These are assumptions But I think I am right. To check, we would need to have dates of promotions for Graf.
More factual info
DoB : 24/10/1912
DoD : 04/11/1988
Last rank : Oberst
Last unit : J.G. 52
EK1 : 10/10/41
DKiG: 09/09/42
RK : 24/01/42 (398th) as Lt. d.R. 9/J.G. 52 for 42 air kills
EL : 17/05/42 (93rd) as Lt. d.R. 9/J.G. 52 for 104 air kills
Schw. : 19/05/42, same rank, same unit for 106 air kills
Brill. : 16/09/42 as Oblt. d.R. 9/J.G. 27 for 172 air kills.
Graf was promoted to major after his 202th air victory and scored 212 victories at the end of the war.
Regards
Denis