If you study the class C operation, it would be a lot easier to understand the purpose of each device; The values are usually based on specific operating frequencies;
L1 (part of the of the input stage, mainly providing low impedance path to the base of transistor.--best to use an addditional capacitor in series)
L2( inductor used as high impedance to RF signal while providing zero DC bias for transistor)
L3 (used as a energy storage for the output resonance circuit during transistor OFF time)
L4 ( part of the tuned output resonance tank used to keep the output sine wave going during the non-conducting portion of the input cycle).