You cannot just go to the middle of the band and tweak the osc. First, the frequencies on the dial (usually slightly non-linear) are positioned by the factory design. The service manual usually states the following procedure for analog tuners (I'm generalizing here); Assuming you don't have an RF signal generator, at the low end pick a medium strength station at a known frequency of about 90 mHz and set the dial to the correct freq. Adjust the oscillator COIL to peak the output at the correct spot. Then, move the pointer to a station with a known frequency of about 106 or 107. Adjust the trimmer screw on the oscillator section of the tuning cap (not the RF trimmers) to max the output at the correct location. Unless they were accidentally bent, you should never have to touch or bend the actual capacitor plates. The low end will shift slightly. Go back and do the low end portion again. The high end will shift slightly but move closer to the correct point. Then go back and do the high end section again. Go back and do the low end. The location should be closer than before. After about three passes at both ends the dial pointer should line up quite nicely. Remember, align the low end with the LO inductor and the high end with the LO cap trimmer. It's a little more work if the inductor is air wound without a ferrite slug. You will have to squeeze the coil to move the freq down and spread the coil to move it up. You have to use a non-metallic nylon hex head tool of the correct size to adjust the LO inductor ferrite core (although some use a straight bladed slot) and plastic screwdriver tool with a tiny metal end to adjust the cap trimmer. This same procedure is used to align AM radios by using appropriate high and low stations or (preferably) an RF generator.