There's little difference between L1 and L7 from a gameplay perspective, the biggest difference being how Deadworld works, which changed from L1 to L2.
The same adjustment setting bugs exist from L1 to L7, for example you cannot restart after the first ball even if the adjustment is set to do so on any version.
There were enhancements to switch logic and how the optos are handled. This made the game less "finicky" but if your game is set up and working properly, you wouldn't notice this. In some ways, L1 could be considered better because it let's you know if a machine's optos are "on the edge".
Lots of pricing fixes along the way. Probably the biggest change came at the end with the ball save timer adjustment.
Matching the sounds to the L1 game ROM also takes some doing:
https://pinside.com/pinball/forum/topic/tech-judge-dredd-sound-roms-l1-and-l3#post-994184
Bottom line: all JD really needs ROM-wise is Deadworld support, better switch compensation, fixing of the adjustment bugs, support for paid credits and LED support. Most of this you can get already.
To OP - GLWTS - free bump.
viperrwk