S.P.M is Sächsische Polizei Magdeburg, 1920s police in Saxony.
The other is probably a nonstandard WWI marking for Feld-Artillerie Regiment Nr.78, also from Saxony.
Edit: I'm a dummy. Magdeburg is in Saxony-Anhalt, not Saxony, so the M is another in Saxony. I'll have to look it up.