Post a picture of your device anyway, if you're not sure about screen breakage.
A broken screen shows horizontal and vertical lines, but they don't go all the way through, but they will change at the point where the actual crack is located. And by this change in the display you can tell the actual cracked line which is usually not perfectly horizontal/vertical. Sometimes even a star shaped crack if it was caused by punct point of pressure was somewhere in the middle of the display.
Story HD is still available in Europe, I have two of them, so if one cracks I'll just use the display of the other one. If you can find one with an intact display but bricked electronics on Ebay, you could repair it yourself... open both of them, and just move the electronics to the reader with the intact display. That's what I did with my bricked Story HD, using one with a cracked display bought off ebay...
Unlike some other devices, the Story HD can be opened up and closed without leaving a trace, so self repair and battery exchange is entirely possible. Unlike the Bookeen Frontlight which apparently, can not be opened without damaging the front case.