I haven’t seen all-inclusive OEM kit for pressure tanks. I have seen tank rebuild kits on Ebay that sellers have assembled. Because your tank is the older style with the aluminum push button, you will need the nine-hole diaphragm as opposed to the eight-hole diaphragm.
You can modify an eight-hole diaphragm to a nine-hole by using the old nine-hole diaphragm, that you show in your picture, as a template and making a hole for the plunger. Some of us only buy the eight-hole diaphragms because they are less expensive and easily modified.
The upper housing gaskets are made by OMC/BRP and Sierra, or you can make your own. They are made from thick cork sheeting. Lapping the upper housing mating surface until its flat will make it like new again. You get to start out with a new, clean, and flat surface that will seal up for decades.
The fiber washer screw seals can be reused if in good condition. NOS seals are pricey. I have been able to find fiber washers in bulk with the correct ID, but a slightly smaller OD and a matching thickness that work well. One thing about the kits I’ve seen is the screw seal washers are made of thin cork which can crush upon tightening, and they don’t look original if that is important. Use gasket sealer on the upper housing gasket and the screw seals.
Regarding the aluminum button/plunger, use Loctite Blue on the tiny brass nut and lock washer that secures the steel disk to the bottom of the diaphragm. The aluminum button also must be able to spin freely around the plunger. The tiny cotter pin in the button actually goes around the plunger rod in a groove that allows for the button to spin.
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