Hi,
I got a stock Lightning from Nik over a year ago and it is a really nice amp. But still space for improvement.
I don´t know how close it is to the real thing, but my one and also the originals tend to be really bright and
the distortion is too harsh with single coil guitars and also lacks some warm midrange. The higher gain settings I found to be too aggressive and muddy, altough I run it with warm sounding speakers: a private jack and a cannabis rex.
I did some researches on mods and I did some changes, what I call the AC/DC mod...

AC mod:
I changed the volume pot from 1meg to 500k and its cap from 180pf to 100pf, like the AC30 TB channel. Instead of the lineout jack I installed a AC15 top cut control, a 250k pot and a .005 pf mustard cap in the PI section.

DC mod:
Like on the DC-30 I changed the master pot to a switchable control without the cap, so that the master volume is defeatable.

And the tone?
Great  warm tone, wich tends more to the Vox side now. There is still plenty of high end shimmer,
with single coils more than enough. The cut control works better than on the matchless originals, where it is only very subtle.
Now the treble control is useable, I dont have to trun it down nearly all the way, it is over twelve o´clock now.
The midrange is increased and the tone gets even fatter with the master volume switched off.
Without mv it starts to break up with sc´s at 3 and with hb´s at 2 on the volume control.
The mastervolume distortion and attack is more musical, still aggressive but more rounded with a british flavour and less fizzyness.
The best tone I get with an lp without mv and the volume control nearly dimed (use an attanuator!),
singing british class-a crunch in your face!

Now it works better for me