Would it be possible to convert a bascinet into a visored sallet, like this one?
[img]http://www.mackenziesmith.com/assets/images/bellows_sallet_400.JPG[/img]
Or is it just too different? Did any of the sallets have back-points?
Yes, you can turn a bascinet into a sallet. Flemish style Sallets and the conventry style of sallet does have a pointed top, if you look hard enough you can find what you want