They seem to use the Valiant system so I can tell you what a few thing mean.
The next 2 are type...
1M = 1300 Manual
7M = 1500/1600 Manual
8M = 1600 Auto
5H = 1500/1600 Alpine Manual
6P = 1600 Alpine Manual and Auto
7H = 1600 GLS Manual and Auto
I think that would be using the Valiant price scale
Chrysler offered it's vehicles according to price range:
L = Low
E = Economy
M = Medium
H = High
D = Deluxe
S = Sport
P = Premium
And a number ranking system, 1 though 8. 1 is low and 8 high. The higher the number the better the specification.
So a 1300 Manual with a 1M is the bottom the the medium price range
1500/1600 Manual is 7M which is near the top of the medium price range
8M = 1600, Auto, Top of the medium range (they were more expensive than the manual versions)
5H = 1500/1600 Alpine Manual, middle of the high price range
6P = 1600 Alpine Manual and Auto, middle of the Premium range
7H = 1600 GLS Manual and Auto, near the top of the high range
41 on the end is probably the Chrysler NZ country code.
Again I think this is using the Valiant codes
Each body type has it's own number:
22 = Utes
23 = 2 Door Hardtop (Sedan)
29 = 2 Door Coupe (Charger)
41 = 4 Door Sedan
45 = 4 Door Station Wagon
I can confirm this by the fact that my old wagon was BQ7M45#### http://www.carjam.co.nz/car/?plate=jo2977
so 45 for a wagon and 41 for a four door
Valiant codes are laid out the exact same way.
1972 VH Chargers code VH8H29
75 Avenger Alpine 1600 BK6P41
And another colour to add to the list
AQ = Aquarius