Ok, thought maybe you found the long lost Halliburton Mongolia truck.
In 1976 Halliburton placed an order for 30 C500 trucks with Kenworth. Due to various production delays the delivery stretched out almost 4 years with the last truck being delivered late in 1979. The trucks were an 8 wheel drive configuration with single tires on all axles. They were also cab over models.
Round about 1989 Halliburton downsized it's Mongolia operations. 26 trucks were liquidated, 2 were returned to the US, and 2 were wrecked while in service. Of the two that were returned 1 went to Jacksboro TX where it sits today in a storage yard. The other went to Houston and was sold at public auction in 1997. It has not been seen since.
Of the 26 left in Mongolia 5 found their way into Siberia where they are working the oil field up there. Kenworth makes a damn tough truck apparently. The whereabouts of the other 21 are unknown, it is rumored that 3 were appropriated by the Chinese military, converted into troop transports and are serving in Tibet. However this has not been substantiated with any photographic evidence.
The truck that returned to the US and was sold had a large pump mounted on the back for pumping drilling mud. The one in Jacksboro TX has a 4,000 gallon tank to hold drilling mud.
If you happen to see some red paint under all that green then maybe you do have the missing Mongolia truck.
Heavy trucks are something of a hobby of mine. Hope you don't mind me sharing some information with you.