I wouldn't think that the value or tempco are particularly important, unless the resistor is used to compensate for something like temperature.
The board didn't appear to have an other re-work. That 6 band 33K, 1%, 50PPM tempco resistor has been replaced with one of the exact value. You may be right that the value doesn't mean much. The BOM calls for an 18K. Go figure. Probably an update since they weren't using the BUZ80 anymore and the SCR was a different type. Everything else was exactly as called for in the BOM. From what I can tell, any SCR/Thyristor may have worked as long as the voltage spec was high enough. I dunno.
Any idea how that pot (100 ohms) 186 was supposed to be adjusted? I left it as it was. It is paralleled by two 1.5 ohm resistors and then the tap has a 470 ohm resistor going to ground. The adjustment was probably fairly minor.
I'm mentally burned right now. I think I am shutting the shop down early today and go out and pressure wash - lol. I had a very hard time getting it to work until I realized, I installed 1N914B diode 184 in backwards. I think it would have just mimicked the SCR turned on all the time.
When I try to figure out how this power supply is supposed to work, with the secondary feedback through the opto-isolator, I get a migraine. When I went to Electronics school in the late 1970's, switching supplies were not taught, and if they would have, they would have just skimmed over the basics. I have been watching switching power supply repairs on YouTube. Some actually try to teach the theory, some just show the repair. None come close to matching this monstrosity. Keep in mind this is just one board out of five that could have problems. The other power supply boards have the same kind of excellent schematics (sarcasm).
I don't have all the caps needed to recap all five boards. I only found one swelled capacitor and leaking capacitor and it's been replaced. For the future, I need to get a supply of capacitors in-stock. That isn't easy. I haven't found a good 105 degree electrolitic "kit" for purchase that covers most of what someone would need. I am going to go through the BOM and order 10 of every value I see and stock them.
Dave