Clips all sounded good to me Ryan! I'm not sure that tuning in the low end is that big of a deal. However, as is the case with most stuff, some mixes and matches work great to immediately give you the tone you are looking for, and others don't, given the way the inherent voicing of each piece of gear is set, and also the frequency centers and especially the Q of the EQ on the head, combined with the voicing of the bass.
Quite frankly, that's why, even though I love Don's work and have loved MANY of his cabs, I'm still playing the 'off the rack stuff'. From playing many of these 'custom cabs' through the years (and a lot of them recently!), all these little tweaks and size changes and crossover changes and driver changes give each cab its own personality that can move the tone the 'right or wrong' direction for any given player. I wouldn't really know where to begin to 'design a cab', so I personally don't go this route.
However, with a relatively evenly voiced head with powerful EQ (like the F500 I've been using as a test head for these cabs), I'm able to get the low end sounding pretty much the same on all these cabs. It's the top end that is tricky. There is no way you can 'dial the grind in' if it isn't there (yeah, you can use pedals and such, but that's not my thing, and never seems to really give you the real deal). And, it is very difficult to sculpt a different top end (i.e., grindy versus smooth and clean versus sizzly versus bright) even with a couple bands of EQ up there, if the cab is voiced a certain way.
Also, it's interesting how different these various mid drivers sound, and also the VERY different tone you get between running a speaker like the 3015 full range, versus cutting off that upper mid response and shunting it to a mid driver.
I guarantee the 'sound in your head' can be delivered by both that cab and that head. I have no idea if you will be able to easily get there with that exact combination, since literally no one on the planet has heard it but you... that's the magic and also the risk of 'custom' designs and also 'mix and matching' heads with cabs.
Edit: While all your clips were more similar than different, and given my Sadowsky with newer SS rounds is more bright and aggressive and grindy than your bass, clip 5 to me sounded the closest to the clip I posted of your cab.... interesting that was the Fender combo flat!