Thanks J - my second print came out really nicely - I thinned the ink with a drop of linseed oil and really worked it in before starting. This really is a "feel for it" thing, but of my first three tries, only one hit the trash. I managed to get a traditional "gritty" look that's very Gryspeerdt, and a really harsh and destroyed look by scrubbing all the ink off underwater (just the deep shadows held) and inking again.
Amazing amount of control with this process - I'm finding dodging and burning on the print just isn't that critical when you can dial it in with the brush. Really digging this, and if I've got this photoshop-level of finessing by my third print, I'm psyched to really dial this in.