Hi!
If I was making this thing the OP wants the 320k resistor is for, I would start with 1.0 and 1.6 in series or parallel combinations and their decades ! Job done !
What I did want to say is, what about old pieces of T & M that use component values even E192 doesn't come near?!
Where would I find 9.9nF and 932pF polystyrene capacitors, as used in some old Cossor Oscilloscopes, without making an unsightly mess around the timebase speed switch using combinations of whatever can be obtained, for example?
The only way to get these is a "parts mule", and there are a few cases on record of these capacitors failing short–circuit due to "silver migration".
The only answer to this one would be to redesign the components around the timebase speed switch to use what capacitors are available, possibly with E192 resistors !
Chris Williams