I got this knife to sharpen for a customer-it had sentimental value to him but was very dull and the handle was messed up. Either the leather on the handle shrunk, or a spacer fell off.
I made it a new spacer of brass. It looks nice to me, sort of WWI, but it made the knife back-heavy. If I could have done it again, I probably would have made leather spacers instead, but I am pleased with the result regardless.
It involved milling/filing a thin rectangular hole .75" deep, a bit tricky in itself. The knife was made roughly, so I didn't go all out on finish and precision. That said, the slot is a close slip fit and it only fits on in one direction as the tang is not entirely rectangular in cross section.