So, changing the opamp did have an effect on treble. CA3130 being the most aggressive, with NE5534 next. The UA308 also sounds good, and gets splatty and gated with higher distortion settings. OP07 also gave it a nice spongy, woolly splat.
Settled on the 3130, and replaced C5 with 1n. Gives me enough treble at the output, and doesn't appear to have negatively effected the presence pot, except at it's minimum setting.
Compared to my Rat and Expandora, it still has way more low-mid grunt, and compared to my Honey Bee OD, it's still a lot more aggressive, but just as clear after about 9 o'clock on the distortion pot.