are there any ways to refinish the metal at home and still get good results?
No!!!!!!!!!!!!!!!
If you want a rifle that looks professionally finished it needs to be hot blued by a professional. No other way about it.
Cold blueing is for
touch up only. Even if they claim that you can do an entire gun it will not look like a factory finished gun and you will have wasted a lolt of time farting around with it.