This is something that has been on my mind lately. It's not really an idea as such, I didn't really know where it should go. But why are certain weapons bonus melee weapons and others are not? It doesn't make the slightest bit of sense.
An improvised crafted sword gets a bonus and yet a crafted Tonfa blade does not. Likewise the Long saw gives a combat bonus and yet a standard chainsaw does not. As the levels progress the difference because of the bonus gets huge to the point chainsaws for example, about the most iconic weapon in the zombie genre, become obsolete, even the highest bonus unique ones.
The new(isn) mezzaluna axe is another white elephant. It's about the same level as a crafted sword, costs about the same in Hardened Metal, and is completely pointless crafting given it gets no combat bonus and thus is eclipsed by the sword and the Long Saw, the latter being 'ranged' if you want to keep the zeds at arm's length.
Also, have the lower level melee weapons ever been refreshed after the whole vintage thing? There seem to be one or two requiring vintage weapons as base items, the Spiked Bat requires a vintage baseball bat for example.