I don't have it with me to get you a better picture, but I uploaded a picture of a socket 3 heatsink on this thread including the underside. Can anyone recommend a cooling solution from Amazon for an AMD 5x86?
That's what you're looking for, right?

Not all socket 3 have same tabs. The most common Soc 3 is offset big tabs but have seen some w/o tabs and some with small tabs. The hold down for offset big tabs is a wire not a typical clip, similar to this picture but smaller. I do not have one but then again most 486 heatsink are using "grabbers" like in jakethompson1 link. The overall length needs be 62mm with near perfect right angles. added: the dimensions in last pic are the size needed, not the clip size I used as example. Not sure if this helps but added a new picture, and no cannot 3D image the original one...

486 sockets have the ledges for this wire Z-clip retainer is occasionally found and I don't have this in my compaq processor boards, that's main problem.

Cheers,

There's this cross type one. The heatsink for it is (obviously) right below, and yes, "surprisingly" it is OEM equipment for this system on a card. It does come with thermal paste.

There's also ones that only clip on one axis.

Unfortunately I don't have better pictures of that one. The hooks are just simple rounded metal strips that bend inward slightly. The whole assemblage flexes. You slip the hook under one side, and push down hard on the other, hoping you don't break the ceramic, until it pushes past the ridge of the chip on the other side and gets stuck.

Actually, on this particular design it's quite hard to push in without a screwdriver, and there's no place for a screwdriver to hook, so you'll have a screwdriver at high tension pushing this flexing metal strap down, hoping you don't slip and stab your motherboard to death...