> will a 5k log pot work??
A dual 5K audio (preferably reverse-audio) will "work", though not much will happen in the left end of rotation.
> I would need a double pole switch, correct?
Correct.
> the values for a gain switch
Yes, a switch may be easier to get than this oddball pot. But computing gain-set resistors is hard work, and quadruply hard with the 2-stage design.
......off the top of my head, these emitter-emitter values will work:
1st stage: 27, 38, 54, 76, 110, 151, 220, 300, 440, 1K, 2K
2nd stage: 39, 54, 80, 110, 160, 220, 320, 440, 1K, 1.5K, 2K
That should give you 6dB steps, more or less, covering about 72dB to 20dB. Steps will be a little short at the high-gain end, and a bit erratic at the lowest gains, but usable.
Those are the effective emitter-emitter values. The actual resistors will be less, because we want to use a Shorting switch and series the resistors. So for the 1st stage the actual resistors run:
27, (38-27)=11, (54-38)=12, (76-54)=22, (110-76)=34..... (2K-1K)=1K