Below is are images of a few nice 1891 5c varieties starting with a A/V. At first glance, the A/V appears like a plugged V. But with a microscope its easy to see the doubling at the top of the V (which is sort of visible in the blow-up of the V). Not shown is the Double T in GRATIA.
There is also a image of a Double 18, and an image of a Double CANADA (but the Double CTO is not shown). The last two images are a Bold Date and a regular date.
There are many varieties such as this in the 5c Victorian coins, in fact in all the Victorian coins. There is also a lot of varieties in the newer issues of 5c coins from King George VI all the way to the present. And many of them are inexpensive to obtain.