This any use?
Google pulls this up for US serial numbers
Digits
1 Country: S = UK
2 Manufacturer: A = British Leyland/Rover
3 Vehicle Make: L = Land Rover
4 Line (model)
D = 90 & 110
H = Range Rover Classic
J = Discovery
N = Freelander
P = Range Rover (mk2)
T = Discovery, Series II
5 Series...