No, it does not work that way. Every turn of every winding is magnetically coupled to every other turn in a transformer. Shorting one turn is pretty much the same as shorting all of them. If you connect to only pins 1 and 2, the you have half as many turns connected to the rest of the Conqueror circuit. Since inductance is proportional to the number of turns squared, you get one quarter of the inductance. For example, a 1H primary winding would become 0.25H (250mH). The inductance of inexpensive audio transformers is not well-controlled in the manufacturing process. As long as a minimum inductance requirement is achieved, then the transformer meets spec. This means that you can buy five 42TM013 transformers and get five different primary inductances.
If you want to nail a specific inductance in a circuit like the Conqueror, you are better off using a Wah inductor. Those may have a 20% tolerance, meaning that a 500mH inductor could be between 400mH and 600mH and meet spec. Not to worry though, the resonant frequency of an LC circuit is proportional to the square-root of inductance. This means that if the inductance is off by 20%, the resonant freq is off by only 10% (in round numbers).