I don't mean to come across as defensive. I have little invested in this piece (literally, I think I paid about $100).
I know it's somewhat of a train-wreck, but I would like to learn a bit about how to work on these. I don't have anyone to learn from directly, so I am learning what I can glean online.
I really just wanted input on the best way to solve the issue of the sights. I think it's probably best to just order replacements and fit them.
As for the buttstock, I am fine leaving it as-is. I suspect it would be a lot of work to outfit a buttplate, and as you say, it's not worth that much effort. (I must admit, though, it feels comfortable enough when shouldered.)
If it ends up shooting decently, I may make it my default chunk-gun. If not, it's no big deal. Starting off with some ugly, hopeless rifles will help me appreciate the nicer stuff down the line.