Over stressed Trusses

We are about to buy a 1970s stone built house. Upstairs the stone work stops at the sides of the windows and there is some sort of panel above the windows. The problem is that the panel is set back, more or less the thickness of the stone work, so there is no lintel across the outside of the wall.
The roof is made with trusses which as we know rest on a wall plate on the inner skin. How ever because there is no additional support from the outer skin over the windows and the eaves are rather wide (2' ?), the excessive overhang where this panel is (30"?) has caused them to droop, say about 1 1/2" over a 10' long window, rather less over the narrower windows.
The Rolls Royce solution would be to install a proper lintel. But I am thinking that if I sister up some more wood on the ends of the trusses I could pull them back straight.
The roof it self looks good but a bit bumpy because of the wobble on its front edge.
Frank

Are these actually trusses, as trusses won't tend to deform.

If so, then are you talking about the leg of the truss from the plate to the gutter?

In any case, it would be very unlikely that you can pull them back.

And these legs would not normally get any additional support by a lintel on the external skin. So is there another cause?