I went to the London imperial war museum this weekend and spotted a picture of British forces operating in southern Ireland and the caption dates the picture to after WW1 in 1920's, one thought a friend said was they were copying the friekorps in Germany who at the time had a pretty bad ass rep, any thoughts?
If these are British forces in Ireland during the Irish War for Independence, just to situate the time period, we're talking about 1917-1921.
The NSDAP didn't adopt the swastika (facing in the other direction from the one in this photo, by the way) until 1920, so there's a good chance this photo might predate NSDAP use of the swastika.
Also: while the Freikorps tended to be right wing, and while a number of Freikorps members would go on to become prominent Nazis, the Freikorps were not synonymous with the NSDAP, especially in the period immediately after World War I. If anything the Freikorps were far, far more numerous, prominent and influential: in 1920 the NSDAP itself was only something like 2,000 members.
While the swastika did have connotations among Voelkisch German groups, its use was fairly widespread outside of those groups, even being used by sports teams.
Some info on specifically how the swastika came to be adopted by the NSDAP:
This answer by /u/elvesandnutella and /u/Killfile
This discussion, with some great info from u/Mqn724
This answer from u/Georgy_K_Zhukov