Still have a small - 3" or so long - sharpening stone with two different sides. All the #11 blades I've used for years now need a wipe down the 'smooth' side of that stone before using from new. As #11s are hard to find, I seem to have a lot of Revell's take on them, and am too tight to toss them and buy any more
Knife handles - those round ones are an accident waiting to roll off your bench and head for your foot. Oddly enough, in an era when cars are designed so you can have safe crashes in them, finding 'hobby knives' that aren't round in section is fun - been looking for one for weeks now after a 'failure' of an ancient one.
Read recently about looking around office supply stores for a widget designed to stop pencils etc rolling off desks. It looked like a triangular section piece of rubber a couple inches long with a round hole through the middle. You shove your round sectioned wotzit through it, the triangular outside stops it rolling off desks etc. Sounded a good idea for a round balsa knife.