If the signal coming in is too hot, you may be getting clipping in the first stage of the reverb block. The first opamp stage has a gain of 7.4. (R3 200K / R2 27K). Try reducing R3 to lower the gain a bit. If that works, you may find that the output level is now below unity.
No problem! You can recover the signal level by increasing the gain on the last opamp stage. It has a gain of only ,84. (R7 6K8 + B10K) / R5 20K. Try increasing R7 first. If that messes up the pot tracking, you could replace the pot with a higher value and adjust R7 to give you correct pot rotation. I hope this helps.