Do it this way:
Remove T1 and wire a 50kB pot to it instead. Remove C38 and put a 10k in its place. Jumper pads 3&2 of the Blend pot on the PCB (but don't solder pad2 yet - you need to connect something else there.
Remove R47. Solder lug3 of a 50kA pot to pad1 of the Blend pot on the PCB. Connect lug1 of the new 50kA pot to ground. Solder a wire to lug2. On the other end of that wire, solder a 10k resistor. Now solder the other end of the resistor to pad2 of the Blend pot on the PCB (the one I told you not to solder before).
Illustration below. This still isn't perfect because the two 10k resistor act as voltage dividers when one pot is grounded but it will get you much closer to what you want. You could make R2 a 22k or 47k instead to reduce this problem...it just depends on how high you set that Level control (BTW - you don't need to remove or fix the Level control for any of this). Also, you can use a 50kA for pot1 as well...it's just a matter of preference. A 50kA will allow for more subtle blends of the wet into the dry signal.
Remove T1 and wire a 50kB pot to it instead. Remove C38 and put a 10k in its place. Jumper pads 3&2 of the Blend pot on the PCB (but don't solder pad2 yet - you need to connect something else there.
Remove R47. Solder lug3 of a 50kA pot to pad1 of the Blend pot on the PCB. Connect lug1 of the new 50kA pot to ground. Solder a wire to lug2. On the other end of that wire, solder a 10k resistor. Now solder the other end of the resistor to pad2 of the Blend pot on the PCB (the one I told you not to solder before).
Illustration below. This still isn't perfect because the two 10k resistor act as voltage dividers when one pot is grounded but it will get you much closer to what you want. You could make R2 a 22k or 47k instead to reduce this problem...it just depends on how high you set that Level control (BTW - you don't need to remove or fix the Level control for any of this). Also, you can use a 50kA for pot1 as well...it's just a matter of preference. A 50kA will allow for more subtle blends of the wet into the dry signal.
