I'd like to know too. What's the difference between the W70D and W70D MKII? I tend to think it could be a switch from the "fried egg"-style tweeter to a dome tweeter like on the W70E. Or is it a woofer variation? Isn't there a W70 4-way AND a 3-way? One with a 15" and 1 with a 12"? I could be thinking of a different model than the D, but it's all so confusing trying to decipher the history of this company - especially with the fire destroying the possibility of a real-deal Wharfedale historical site. Now it's up to the fans and collectors.
And thanks to the OP (if he's still a member - This is a kind of an old thread) for putting up the spec sheet files. Good stuff to hang on to. I have W60's (the slightly-later W60E's with a 12.5" woofer, 5" midwoofer, and a dome tweeter that I believe was used for most or all of the "E" models). I'm pretty sure the "MKII" D models are very-similar to the E models. Even though the D's are rear-loaded (E's are front-loaded), both versions are a sealed, acoustic-suspension design with a more-American-style speaker sound than previous Wharfedale models. I've had my W60E's for about 10 and a half months now, and I'm happier then I've ever been with them. They seem to have gotten better over time. Receiver/amp choice is key with these things. You really want a low-powered, early-mid '70's, SS receiver or amp powering a set of W60 E or W70E's. Great sounding speakers for all kinds of music.
For the W70, there were several different versions throughout the years. There were the early W70's (and I believe W70B's and W70C's), which I believe had alnico-magnet drivers and a sound that had much in common with early Bozak speakers (more-suited for classical and jazz music - A very-warm and glorious sound, but with rolled-off highs). And the introduction of the W70D saw a dramatic shift to a more-American-style acoustic-suspension design. But I think there was a tweeter change AND possibly a woofer or midwoofer change on the W70D. It's a strange and hard-to-categorize speaker.