The parts are described in the manual's parts list.
The large resistors feeding the 0D3 are 20K, 10watt. They are in parallel, so a 10K 20 watt (or greater) resistor would work equally well. The resistors are rated for much more than the actual power dissipated, in order to reduce the resistor temperature, but they still get pretty darn hot. Make sure the any new or different resistor(s) are able to dissipate that heat.
The 0D3 cap is rated 0.1uF 630v. When the circuit was being developed, we tried a 0.056uF teflon cap (Russian mil-spec surplus) which was an audible improvement. The maximum capacitance is 0.1uF according to the 0D3 spec, and it becomes less effective the smaller the value used. I would stick with a 600v minimum rating - it normally operates with only 150v, but if the 0D3 is removed of dies then it will see the full power supply voltage and the initial transient before the other tubes start to conduct will be pretty high - 500v or so.
