Without making any serious misstakes with neo-magnets I have realised that a man should NEVER carry a big magnet in each front pocket of his pants...
Interesting point abot losses in a pancake motor! I didn´t think about that but it seems very reasonable. Without an advanced workshop this approach is impossible anyway. The golfcar/forklift motor approach is probably a lot more DIY-friendly but but I guess that solution demands different gear ratios when working as a starter or as a dynamo. The low gearing needed for starting will force the motor to very high speed when the engine is running fast. This will increase wear of the electric motor and perhaps even cause it´s rotor windings to move... Maybe it´s not that bad to have a separate starter and alternator after all...