There are still many good original examples of the FF33 to be found. Most survivors have been re-used in some capacity after the war, sometimes leading to replacement of parts or (minor) modifications.
Norwegian examples are relatively easy to spot as the Alphabet spelling table on the lid has been replaced. So check that the Alphabet spelling table is correct first.
One of the weak points suffering wear and tear is the handset cable. Originals have a brown cloth insulated cables.
FF33's are typically Wa.A stamped on the bakelite connection plate, this has usually been left in place but in some rare cases these markings have been ground out. The markings on the metal give you the serial number, the manufacturer and sometimes an "E" to show that the frame is made of iron.
There is supposed to be a bakelite battery compartment which is sometimes missing, so check that the compartment is in place.
As time went on, materials used in manufacture changed, it is always nice to have the accessories like the winding handle and handset consistently dated, but in most cases these bits have been mixed up so you may be searching a bit longer if you want everything "matching"...
Digging deeper, sometimes the original microphone or speaker unit has been replaced after the war, so it is worth checking the correct types are in place (if you have one of the mentioned "green stripe" FF33's, your microphone should have a green cross on it...)
The internal electronics of the phone are not often messed with although Siemens could service them and carried spares well into the 1970's. You could check that the manufacturer of the ring generator is consistent with the stamping on the frame and that there are no loose wires or components missing.
Where things are getting difficult is with carrying straps as relatively few originals survived. The good old militaria trade has responded in time honoured fashion with fakes, re-stamped foreign and postwar versions and fantasy pieces so do your homework before committing any of your well earning money!
Overall though you should be able to find some good examples without too much trouble and they are simple and fun to get back to work. For further reading you can go here:
https://www.kriegsfunker.com/pdf/Ger...20of%20WW2.pdf
...or some of the excellent websites on German phone equipment available these days
regards,
Funksammler
FF-33 Identification
Linear Mode
