So both GE+CU and GE+CV crashed?
Yes.
GE+CU (Me 309 V1) was repaired after the accident.
However, GE+CV (Me 309 V2) made its first flight with Karl Baur at the controls, but had an accident on landing, and ended up like the one in the photo. Mischievous Karl
After that, the Me 309 V2 was not repaired and probably scrapped.
Are those external balance weights bolted to the propeller blade hubs?
In the photo, the top propeller looks like that, but I'm not sure about the bottom two propellers.
Edit:
If you look closely again, you will see that the balance weight in the front does indeed appear to be attached with bolts. You can't see the base of the balance weight at the back, but it is probably bolted on as well.
Were these aircraft flown by the allies post war?
Nope.
Me 309 V1 (GE+CU) was abandoned in the field after it was rejected in 1943. It was later found by the US Army, but was probably scrapped. The third photo in my post #48 is the Me 309 V1 taken by the US Army.
Me 309 V2 (GE+CV) was not repaired and probably scrapped after it had an accident on its first flight.
Me 309 V3 (GE+CW) was destined for export. This aircraft was purchased by Lieutenant General Osamu Ohtani, a Japanese resident military officer who was interested in German technology at the time. He purchased the Me 309 V3 and a set of drawings for 1.2 million Reichsmark.
However, the Me 309 V3 was destroyed in a night bombing run that lasted from February 25 to 26, 1944.
Me 309 V4 (GE+CX) was also destroyed in an air raid.
As you can see, all of the prototype Me 309s were either scrapped or destroyed in air raids, and unfortunately were never flown by the Allies.