And this image shows why...
I bought an extra thumb latch years ago, and besides it not being case-colored, it too had the same defect with the slot & sight not aligning with the rib & front sight of the Schofield. You can't clock the barrel as it's 1-piece with the frame and I didn't want to try bending it, so a buddy suggested I simply glue a 1/16" piece of plastic to the left side of the front sight and that would put it right on (per the calculations I ran).
Thought about doing that, but then I thought about looking for a piece of brass or pewter -- tougher than plastic, but not as difficult to work as steel. Anyway, I found an old pewter hat pin I was not using and after drilling the pin out that held the front sight (as it would not budge), then I carefully fit and steel-epoxied the pewter pin to the left side of the front sight and made a new brass pin to secure it (which was tapered for a tight fit). Then I carefully filed the pin almost flush on both sides, just the thickness of electrical tape proud of the barrel rib. (I used a hole punch to put the right-sized hole in the tape so all the file could cut was the pin itself -- a neat little trick I though of.)
Here's the sight picture with the wider front blade installed.
You can see the wide notch -- that's another reason why I didn't want to file away from the right side of the Vee notch, as it's wide enough already.
And here -- you're either gonna love it, hate it or laugh!

Here is the new front sight blade, from the left side!
Cheers!
Old No7