There are quite a few Sudanese AR10s in Canada. Some are war-worn junk, but there are also Sudanese (and other) Dutch AR10s that came direclty fromm the factory, never having been carried by a soldier.
Theere are two major variants of the bolt heads. The earlier bolts (Hollywood, Cuban, Sudan, Transitional) had narrow lugs that look roughly like DPMS/armalite lugs of today. The later Portuguese contract rifles had really wide bolt lugs. In Pikula's book and the AR-10'er newletter it states that a narrow lugged bolt will work in a Porto rifle. There is no reason to try this. If you have a early narrow lugged bolt and want a Porto bolt I will make that trade in a heartbeat.
The narrow lugged bolts had some design details changed in order to add strength. Unfortunately, these bolts tend to fail with one lug shearing completely. As a result the narrow lugged bolts are scarce.
It is possible to re-barrel your Sudanese AR10 and solve your bolt problem. In Holland it is not uncommon to see a Sudanese style AR10 with a Portuguese barrel and bolt head. This can be done using the Portuguese handguard system or modifying the barrel to accept the Sudanese front end.
It is also possible to put a DPMS 308 barrel and bolt together in your AR10. This requires shimming the barrel extension to fit the upper. A custom firing pin is required as well. I know of two rifles in this configuration.
Below are some bolts, from left top right:
Hollywood, Sudanese, Portuguese, Transitional