I would vote for repair first, for windows on a historic house. But if repair simply wont work you should look at top quality custom aluminum clad windows from a company like Marvin. Vinyl is not appropriate for a historic house. In our area the restoration society (which provides low interest loans for historically-respectful renovations) will not fund projects using vinyl replacement windows. Windows with aluminum clad exteriors and wood interiors, however, are covered.

I agree with feeny, I would first find out about repair before replacement.

The best solution (probably the most expensive) would be historically appropriate black steel frames.