I have a used Thunder 9 with a missing rear sight blade.
Click photos to enlarge.
I thought I might replace the sight, so I ordered one from Eagle Imports for $5.

This is what I got. It's the exact same sight that's on my 9UC and 45UC. It's polymer or plastic, not steel. If you try to adjust your "drift adjustable" rear sight with a brass drift pin, you could scratch, mar, or damage your rear sight. I use a rubber mallet. The cloth might be a good idea. Just don't get too carried away with the mallet.
p-t-max
I'm no expert, I'm just, well---opinionated!
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