555 IC as servo driver

tolerances of my resistors are 20% so I assume you can round values if using silver or gold stripe(band) resistors.

I have not seen silver and gold bands on resistors for about 40 years. The widest tolerance you can get these days is 5% ( old gold band ) with 1% resistors being a fraction of a cent more expensive.

Anyway because there is a pot in the circuit it doesn't matter. Only with R1 might it matter a bit, but not much.