[Arran]

With regard to the resistors, with few exceptions, you should be able to test them in place. The exceptions would be if the resistor was connected in parallel with a coil or a transformer, since those are often of a lower resistance then the resistor. One resistor to pay close attention to is a pair of wire wound resistors on one form, listed as part number #58 on the schematic, one or both sections can become open circuit. With regard to replacement resistors make sure that you get replacements of a high enough Voltage and Wattage rating, in some cases it doesn't matter like for a grid or cathode resistor, but watch out on the plate load resistors if the voltage is above 250-300 VDC or so. 
  Fortunately since this is a seven tube set there are not as many paper capacitors to deal with as a larger model, so restuffing the Bakelite blocks or even any cardboard tube types would not be that time consuming. Morzh (Mike) has a fairly efficient method that is permanently posted in the tech section on here.
Regards
Arran