Lyman 48 sight repair

[Mustang51]

Anyone have a source for Lyman 48 sight repairs?

I bought a Swedish target rifle that has a l
Lyman 48M sight on it. Elevation knob turns, but doesn't raise the sight.

 

[troy fairweather]

are the little set screws lose or is the half nut striped.

 

[Mowgli Terry]

Make sure the staff is engaged. The sight may be clogged up with grease.