3.5 and 7 MHz are harmonically related. As a rough rule of thumb 10 uH requires 200 pF to resonate there. If you wanted to preserve the LC ratio then you'd use 100pF to resonate with 4.7 uH on 7 MHz. In other words double the frequency, halve both values.
What if you wanted to leave the 10 uH in and bring it to resonance on both bands? Then instead of doubling (or dividing by two) you'd need to multiply the capacitance by 4 (or divide by two). You can get away with this for adjacent bands but not if they were too far apart (eg a frequency ratio of 3 or more to 1).
In the case of 3.5 MHz and 10 uH you still need your 200 pF. For 7 MHz though as you're keeping the inductance the same you need a quarter the capacitance. That is 50 pF. If you only have 100 pF capacitors below is a possible scheme using a double pole double throw switch.