Those are resistors. When there's a letter R followed by a number on the reisistor, the R would be the decimal place. R31 is a .1 ohm. It looks like R27 used to be a .33 ohm.
To me they look like resistors. R26, R27 - most likely emitter resistors for BD transistors, and 3rd (black resistor) is in sequence with 47nF capacitor (Zobel circuit)