You know it Chanks

No seriously. It's been over 25 degrees for the past week.
Ok, just got home and I have no way to crank anything as all children are asleep right now and I'd like it to stay that way. Did some reading on the trip home from Gotland and I reckon this will get you in the ballpark. So here goes...
D+ is an op-amp OD. Bodes well. It has symmetrical clipping. Check. It has a slight bass rolloff which gives a really tight wound.
Randy ran this through a NMV Marshall running somewhere in that fantastic no-mans land between clean and dirty. Apparently bass was on zero, mids fairly cranked, treble on 7, presence up a bit.
So...
Unless you have super low output pickups I'd roll with gain switch down (that is, only the first gain stage).
Don't adjust the gain knob yet.
The clipping toggle is a tough one. Up is symmetrical clipping, just like the D+. But the upper position is LED clipping, whereas the D+ uses silicon diodes. The lower position on the clipping knob is a silicon diode, but it's working all on its lonesome, so its providing asymmetrical clipping. To my ears, the silicon diode sounds closer to the demos of the D+ I've heard on the internetz. But, I also think the LEDs have a little more presence than the silicon diodes. Begin with the switch down with the silicon diode. I'll get back to that point....
Mid frequency toggle is easy - toggle down for a mid boost around 800hz. To my ears that just sounds super marshally.
Bass cut: Put the toggle in the middle position and cut as much bass as you can. This will give you a really tight distortion, and you will hear any and all mistakes you make... It will definitely make you appreciate how awesome Randy was

Knobs:
Start with the volume at 12 o'clock. Mix on full.
Crank the mids to somewhere close to full.
Adjust the gain until you get a distortion that is punchy but not too saturated.
If the mid range is too honky, dial it back a bit and compensate with a little more gain. Especially so if you are playing at bedroom volume. If you are playing loud fuck it, nail that mid range.
Start with the bass at 12. The bass cut switch should get you in the right ballpark in terms of bass response, but you may need to cut more. The D+ cuts a bit, and the Marshall tone stack with bass on 0 cuts a lot. Randy would have gotten some bass response out of his 4x12s and the massive volume he was using, but it's a sound that leaves a lot of room for a bass guitar. So this is a bit rig/volume dependent, and whether you are playing by yourself (you'll itch for more bass) or playing with a band (cut that bass Randy style!).
I'd crank the treble up to at least 3 o'clock and take it from there, depending on your rig.
That should be a good start at least!
A final note about clipping diodes - Randy had the presence pretty high on his Marshall. This can't be replicated at all with the Elements, but if you find that you're at the right amount of treble and the overall sound is still a bit "flat" then I'd change the clipping switch to the upper position and bring in the LEDs. To my ears they have more "presence" than silicon diodes - but that is using presence in the descriptive sense and not in the way it is actually implemented in an amp. Meh, you know what I mean.
I'm kinda tired so if that didn't make sense hit me up. If you get a chance to try the settings above out before I do, and it doesn't sound right, let me know what sounds wrong and I'll see what I can come up with
