The first very few AR10's were made in Hollywood, CA by Armalite. Then came the Dutch, who greatly omproved the design. The various Dutch incarnations of the AR10 were many, but generally fall into three broad classes: Sudanese, Transitional, and Portuguese.
A Sudanese contract rifle is shown below:
I have also been told that there is a Guatemalan contact AR10 that looks much like the Sudanese, except for the bayo lug to the flash hider:
The Portuguese contract rifle has completely different handguards and a larger stronger bolt. The Portuguese handguards are 4-piece, with metal heatshields covered in bakelite. I have been told by a Dutch gunsmith that wood was used for early rifles.
Many parts are interchangeable between the Sudanese and Portuguese variants. A Transitional rifle has a Portuguese barrel+bolt+handguards and a Sudanese upper+charging trigger+lower.
So many of the partes are interchangeable betwen these rifles. My Dutch buddies tell me that when the Artillerie-Inrichtingen factory closed many of the parts fell in the hands of local builders who made custom rifles that do not fall into any of the normal classes.
A few hundred semi-automatic AR10 live now in the US, and sit upon domestically manufacturered semi-auto lower receivers. Some of these rifles served time in Africa, and are pretty much worn out. The most worn out rifles tend to wear reproduction furniture. Below is a Portuguese rifle with new wood.
It seems that some of these Portuguese rifles lost their original metal handguard heat shields. That is the reason why it is common to see one-piece reporduction handguards for the Portuguese. Here is an example of wood and plastic.