Just some info for those adding a stock
If you manage to find a stock most likely it won't come with the correct rear end for the Bren required to mount it as this is an extra part from CZ not part of the stock.
The part number is 3701320001 or 3701-320001-ND its called Rear Head Complete
On the Bren pistol you have this part
The new part looks like this
End result looks like this
I have not bought the part from CZ USA but looking at the pricing I have it should be around $40-$45 if CZ USA don't sell it or won't because of 922r concerns then you can get it from the pistol brace kit