Sharp knives

[JumbleDuck]

Can anyone tell me what the small blade on the back is for, looks like what my grandfather used to use for reaming out his pipe.

Bingo. It's the "reamer / punch" which was originally called the "awl" until they gave it a sharpened blade. You use it to make holes in things, or to make existing holes bigger.

 

[Vara]

If the primary purpose of the knife will be to cut rope, it's useful to sharpen it with a coarse stone, the sort of thing used to sharpen scythes and sickles, gives the blade a bit of bite.

I use Steak knives bought from Auchan as emergency knives, about €2 each, which hack through line very efficiently.