Backflow Replacement

[tropicalexplorer]

Due to last weeks below freezing temperatures in Austin it got to my backflow which now needs replacing. I have found the replacement backflow and it is on order. I can't seem to locate the grey PVC adapters as shown in the photo which attaches to the backflow and the 1" elbow. Any suggestions on where I can purchase them or a suggested replacement part?

 

[Fitter30]

Use pvc male pipe adaptors to glue. Make them in all pvc and with steel threads
https://www.supplyhouse.com/Spears-436-007-3-4-PVC-SCH-40-Male-Adapter