Well... I'm the last person that should be doling out advice, considering I can't seem to let go of anything
Still, I'll give it a try...
You should first get to grips with the KP and find out if it meets your needs. It has some important image quality, performance, feature and ergonomic differences - some which you might find very positive, others slightly limiting; but this will depend on what's important to you. If you find the KP to your liking after a little while of shooting, then it's a keeper. If not, you can sell it whilst it's almost new, and get the best return of any camera in your collection.
Assuming you keep the KP (and I suspect you will), then you might consider letting the K-3 go. It's still fetching decent money in the used market, in lieu of any release date for the new APS-C flagship.
Are you getting good use out of the K-01? If not, there still seems to be demand for this body, and relatively limited supply compared to other models. Prices vary considerably, but if yours is in very good condition, you might be surprised at what you'd get for it.
As for the Z-1, it depends on whether you're going to continue shooting film. You won't get a great deal for it, so if it's a good example then it's almost worth hanging on to "just in case". But if you've scratched the itch for film with your FA Limiteds and other lenses, you might get enough for dinner by selling it - and someone else can enjoy shooting it
If I owned your set of cameras, based on my own likes, dislikes and preferences, I'd probably keep the KP and K-3II, and sell the K-3, K-01 and Z-1. But, as I've already admitted, I just can't seem to let any of my gear go. So I'd most likely keep the lot