Hi Troels, well, bit of an update here. I've had the speakers finished for just over a week now. Has been a journey in the making of them and one that has continued on afterward.
 
Initially I thought the speakers were a little brash in the high end (with the higher R1 value installed). My existing shelf unit was too high for the designed listening position - I tried sitting on a cushion in the interim!  But within a few days I made time and cut my shelving down, knocked up some stands of appropriate height - to get the mid driver at ear level.
 
This brought everything together. I definitely feel that I experienced speaker break in as well. They've settled beautifully.
 
I have a single sub with an old Velodyne SMS controller on it. Running the sweeps on that with the sub off showed the 3WC-10 comfortably doing 30Hz and then some. There's very little work left for the sub to do (though I plan on making a second sub to even out room response). I'm working towards revised shelving to get the records lifted up out the way and bring more breathing space around the speakers too.
 
But truly, they're marvelous. I love the speed and weight of the bass and upper bass, these registers now have tone. There is now a presence and effortlessness that had been lacking with my previous small 2x monitors.
 
Thank you for your design and assistance.
Kind Regards
Pete.