Rollei serial numbers

1. Rollei 16
2. Rollei 35
3. Rolleicord, Rolleiflex TLR, 6×6 cm
4. Rolleiflex TLR, 4×4 cm
5. Rolleiflex SL 66
6. Rolleiflex System 6000

Rollei cameras from the 110 series have no serial numbers on the camera bodies. The lens numbers count as serial numbers.