question i'm asking is exactly what it says on the tin i suppose,

i know theres a decent bit of variation within both types, and some overlap but generally what features characterise a kopis to distinguish it with a falcata GENERALLY so that while looking online for one that i know im buying/ making something thats more a kopis than a falcata

There's a lot more variation among kopises (kopides?), so you can find a kopis that can't be a falcata. But the typical Macedonian kopis is pretty much the same as an Iberian falcata. Except that falcata might more commonly be double-edged on the point-side of the bend in the blade. Whether or not kopis blades are the same is hard to tell, given the condition of many. Some look like they might be double-edged. Some kopis blades are double-edged all the way, but this is unusual.

AFAIK, the only other real difference you'll find between the look-a-like kopis and falcata is that the falcata might have non-Greek decoration on the hilt.

From what I've seen, the kopis tends to be straighter or slightly curved along the back edge, whereas the falcata always has that distinct angle (like a kukri). Kopis blades may have a rib or ridge near the back edge, but falcatas are more likely to have a series of fullers. There can be differences in the hilts, too.

Scabbards are even more distinct. The kopis has a scabbard much like the xiphos, with a throat that matches the width of the guard and often has the U-shaped lug or tab on top, which aligns with a matching notch in the guard. The chape will also follow xiphos fashions (which are varied!). But the falctata scabbard typically has a metal frame, with side gutters, cross-bands, and suspension rings. And there may be a small "by-knife" with its own sheath built into the sword scabbard--I don't think those ever show up on Greek swords.

The Macedonian kopides that I've seen (the Latsis Foundation ebooks are good sources) are pretty much the same as the ones from Greece proper, from what I can tell. I haven't seen any that could be a falcata. Mind you, there may certainly be examples in museums that are mislabeled! I've seen that happen. Without a reliable find-spot, I'd be careful about claiming it's one thing when it looks like the other.

Matthew

Is this one:
http://www.metmuseum.org/art/collection/search/257576
then mis-identified as Greek?