Help the newbie

Hello everyone, I recently aquired a "new to me engine." I amtrying to figure out what I am looking at here as the 1980 and 1978 heads I have some differences. As far as I can tell I am missing some shims or something. The other two heads I have do not have the recesses above the valve stem. What I am wondering is what has been done to this 1980 head that I have. I can already tell I am missing 12 spacers (not sure if thats what they really are). This head did not have the buckets. Should I use the buckets I have from my other heads? Or just rebuild my 78 head? The 2nd one from the left still has the spacer in place. I only have 2 spacers. Any help will be greatly appreciated as I put this poor 78 back together.

Those "Spacers" are the shims for the valve clearance adjustment, which go on top of the valve stem, then the "Bucket" on top of the shim, then of course the cam. You can get some used buckets or use ones from your other head if they are correct, then reset the valve clearance. You can buy the different thickness shims on line or from your dealer, I buy a kit of them from K&L, they are inexpensive.
But If it was me I would make sure of the valve job before starting that process. You might consider taking your heads to a qualified motorcycle compatible machine shop to get the work done.

Welcome to the forum, Zefyr. There are two variants: shim on top and shim under bucket. The KZ1000's are all shim on top, although for high-lift cams and high-revving motors changing to shim-under is a popular modification (with high-lift cams even mandatory) to keep the shims from being spit out. The shim-under are standard in for instance the KZ650.
The head in the picture looks like a KZ1000. If it has not been modified, the valve stems should protrude very slightly. If this is so, you need buckets with a small ridge on top for the shims. If there is instead a recess with a diameter of about 10mm and a depth of some 2mm, it is a shim-under type in which case you'll need flatheaded buckets and small diameter shims.
Do you have a better picture?

PS:
- It is handy to include your bike(s) in your signature, or name the type of bike your working on.
- Get the factory manual for your bike, it will save you a lot of trouble and is way better than Haynes/Clymer et al. They are usually available on Ebay.
- Does the head have the original camshaft caps?