For a small signal analysis, we ignore DC values and we say that Re has an AC voltage across it that is nearly equal to the AC voltage on the base. If the circuit were an emitter follower, it would have a voltage gain of about 0.99. We're not interested in the output being across the emitter resistor but, it's still important for what follows.
We make a reasonably accurate assumption that for AC signals, Vb = Ve
It therefore follows that the AC current thru the chain of transistors is the base AC voltage divided by the emitter resistance. This AC current flows thru to the collector load impedance (cascode or otherwise).
Because the AC current is the same thru the emitter as the collector you can say (with a reasonable degree of accuracy), that the gain of the amplifier is Rc/Re. But what is Rc or Zc?
Going back to the op's circuit, if Rd were zero ohms, the parallel LC AC impedance in the collector is infinite but it would be plain daft to say the gain was infinite because there are always losses so, work out what the impedance is at resonance and use that as equivalent to Rc in the gain equation mentioned above.
You might also take into account that a BJT in its active region might have a parallel resistance of about 20 kohm (generalism alert): -
Hint: the 20 kohm value is the flattest part of the characteristic shown above in the active region. On this particular graph it looks like 20V/1mA = 20 kohm.