Apart from the meteor hammer/flying weight/rope dart I posted before, I also wanted to tackle the tekagi-shuko (ninja climbing claws also used as weapons), whip chains (such as the seven-section whip), and fighting fans (specifically the tie shan and gunsen, both are which were folding and had sharpened iron ribs). I was going to do a separate entry for hook swords (such as the tiger hook) but now I've found out that the early ones were sharp, the stats ended up being those of the scimitar, so I'm folding them in there. I've also added a Flail entry to the equivalency list in the form of the Chijiriki.
Simple Melee Weapons
Climbing Claws (pair) 1 gp special 1/2 lb. -
More of a climbing aid, climbing claws (tekagi-shuko) are iron bands that wrap around the palms of the hand and also strap to the wrist. 3-4 short iron claws project from the palm to give the wielder increased purchase on surfaces. They also enable the wearer to do slashing damage with their unarmed attacks instead of bludgeoning, but while worn they inflict Disadvantage on most other tasks using the hands beyond striking and climbing.
Fighting Fan 5 gp 1d4 slashing 2 lb. Finesse, light
An elegant weapon, the fighting fan is a decorative folding fan with sharp-tipped iron ribs. Other fans used to fight or defend are either clubs designed to resemble folded fans (tessen) or solid, paddle-like open fans (gunbai).
Martial Melee Weapons
Chain Whip 5 gp 1d6 slashing 4 lb. Finesse, light
A difficult weapon to learn, the chain whip traditionally has seven or nine short, slender, linked iron bars attached to a short handle and tipped with a slashing metal dart.