Welcome to the forum!
I'm not a 99 expert by any stretch of the imagination but you might try the auction sites for the parts you need. As far as scope mounts go if the rifle was not drilled and tapped for scope mounts at the factory then without drilling extra holes you would need to find a Stith mount or there was another scope/mount combo that fit the tang sight holes but I'm not sure about the name "Warner" comes to mind but that could be out to lunch. I'm sure one of the 99 experts will be along shortly to help you out.
Bob
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