555s, RC and LC generator/oscillator circuits are not designed for good accuracy or precision. The best you're going to be able to do is use a checked Mylar cap against a metal film resistor, and even then, for 1% accuracy, you're going to have to use components with an accuracy of 0.75% or better or at least checked to 0.75%, including the tempco. If you need more accuracy, use a crystal oscillator at a mininum (it's more than good enough for 1%, typically good for 0.01% to 0.001%) and divide it down. What you won't get with an XO is variable frequency.
Dean