I don't have any photos but as the resident liberarian
I thought I should contribute this reference book on the black rifle. It's the second volume and it covers the Canadian (i.e. Diemaco) model as well as the latest Colt models.
Note of course that when the book was released Diemaco had introduced soon afterwords the C7A2, C8A2 the C8 close quarter battle (CQB) and the C8CT custom tactical sniper rifle variants
Also it appears that the C7 series can also use the HK grenade launcher as well as the 203
Finally, I read in one of the French cop mags that the DEA has recently adopted an AR 15 variant from Rock Island Arsenal. I think it's called the LR 25 or LAR 25