Your 99 appears to be a spitting horse but the one's that I have seen extend all the way to the rim so I don't think it would carry much of a premium over face value.Jmo Your 2015 appears to be die chips and again I don't believe it would carry much premium over face value. Jmo But they are fun to collect.
Meow keeps stuff like that for fun in the cat hoard. The Homestead is a fairly good example. Shall we call it the snow on the roof variation? And yea, Meow has seen better examples of the horse going for the spittoon. That one is a bit on a weak side, but still fun to put in a cheap flip and admire. They do both seem to be in pretty good condition at least.
Yes, they are minor errors as explained above. Cool finds, but don't expect to get rich off of them. Most minor errors like these rarely carry a premium over face value, but I would consider them 2x2 worthy if I got them in change