An alternative "official" optic is the one we in Oz got from the Germans after they went from the FAL-based G1 to the Heckle and Jeckle G3 and the very nice Schmidt and Bender compact scope.
The earlier Hensholdt is a compact unit that looks a LOT like one of the late WW2 German ZFK 43/1scopes, but mounted on a special dust cover and retained by cheesy thin steel straps as per the ZFK 43/1 and ZF 4 mounting and which are prone to cracking and failure.
Pix and discussion here: Band Mount Hensoldt ZF4 for G1 In Detail - Wehrmacht-Awards.com Militaria Forums
More pix and discussions here: FN G1 MILITARY SCOPE, MOUNT AND BOX? OR???? - The FAL Files
Most of the rubber lense-covers seem to have fallen off / rotted away since the early 1960's; funny how that happens....