(x - 4) or (x + 8)
See link below-
It is the sign of multiplication in an expression.
20-50 usd
1x128 2x64 4x32 8x16
No
About $30
Send it back.
5-100 usd
It's worth between $10 to $15 used.
You can't it is not designed to come apart. Time for a new Scope.
I just paid $10 for a used one. Reg.No.F. 7432C
The typical Marlin 39A does not have a scope. They are drilled and tapped that one can be added.