You have all terminals of both of these SCR available independently, so it really does not matter if they are connected in series.
To test an SCR using DMM try following:
1. Test the diode action between Gate and cathode
2. Now test for SCR turn on: Short gate & anode of SCR with +Ve of DMM & -Ve to cathode. It should show turnon state or low resistance.
3. Now test for SCR off state: Between Anode and cathode it should show. open circuit or high resistance (Note here we have not used Gate terminal)