Canadian Large Cents With Full Serrif On Top Half On Botto

In 1876, ALL 1876's had single serif left foots on BOTH N's. Since the '76 masters were used to make the working dies for 1881 and the beginning of 1882, about half of the 1882's will have single serif left feet on both N's. There is a very scarce 1881 with single footed left serifs. I'm pretty sure that your "two dates" are 1876 and 1882, since 99% of the 1881's had reunched N's to make the N's look full when they started out single, like the 1876's. As a general rule, and general only, the full serif 1882 Obv 1's and the single serif Obv 1a's tend to have the harder to find varieties or die pairings.