From what I can see you can build (out of the box that is) only one "correct" version from the 5th Baulos:
1. New layout of the Anti-Skid pads
2. Hull ammo-bunker-plate still "bolted"on
3. And on some of the later produced vehicles in this batch the deleted "Ammo-door" on the turret. (Spielberger, page 320)
The hull would now be ideal to make a Dutch 2A5/A6 version
From the 6th Baulos on the ammo-bunker-plate was welded ... no more bolts ... so one could remove these to make this area look like on the Tamiya kits. By doing this the 7th & 8th Baulos would be okay.
The 8th Baulose was delivered mostly to the Gebirgs-Panzer Battalion 8 as I recall and there are some pics of these tanks with the "new" side-skirts ... but they were quickly replaced by the "old" ones to spare them.
Funnily I can't recall coming across a Leo with mixed new front side-skirts and "old" ones except in Spielbergers book.
Maybe there is a PE/Plastic part to refit the weld seams for the closed "Ammo-door" one the turret making a 4th Baulos also possible.
Either way the kit looks very promising with a lot of potential.
A "correct" German replication of any possible versions (4th -8th Baulos) dictate the NATO- 3 tone-camo applied.
Can't wait to get my hands on this kit !
Cheers
Christopher