@Glennj here is one for you! The Officer at left-center looks to have early 1919 Major's sleeve insignia.
Interesting photo. To the left of that Major is an American Major or Lieutenant Colonel. The 5. Garde-Regiment zu Fuß Officer at the right seems to have an armband that reads...
Here is a great one I received in the mail yesterday. A little bit of everything in this one! Gibraltar cuff titles, Freikorps Hannover insignia, Machine Gunner insignia, and of course several soldiers with the sleeve insignia of early 1919.
There are at least two former Freikorps fighters in this photo. I think only Bavaria allowed them to wear their Freikorps Abzeichen in the Reichswehr, at least for a time.