Always happy to show off my toys. Surprising about the claim of wearing barrels out in less than 100 rounds, unless that was a result of the full auto fire on such a light barrel.
The EX series were bought for user trials at the same time that Britain bought the X8 (same gun, different designation). There were two variations, the EX1 with it's standard type sight, and the EX2, with the optical sight. Some books say there were 1000 each of the EX1 and EX2 while elsewhere it has been suggested that the numbers were approx 1700 for the EX1 and 300 for the EX2.
The rifles were bought directly from FN in Belgium. There ended up being a steering committee between Canada, Great Britain and Australia to achieve a standardization between the participating countries. The US was also expected to go with the FN, but instead went with the M14.
Production of the C1 rifle was started by Canadian Arsenals Ltd (which was the renamed Small Arms Limited, known to most as "Long Branch") in 1955/56 time period. Within a few years, problems were discovered with firing pins getting stuck and causing full auto or out of battery firing. This was cured with a two part firing pin. At the same time, the carrying handle was replaced with a plastic one and the rifle re-designated C1A1.
I have deacts of the C1A1, the C2A1, and the EX1. Now the quest begins to find an EX2.