A modern replacement kit for the Alps SKCC Tall using Gateron Low Profile 2.0 Switch (KS-33)
The setup it's pretty easy, you have the Gateron switch sandwiched between the PCB and the 3D printed stem adapter.
I got mine from PCBway, their standard service it's fine enough, the thichness doesn't really matter, as long as the switch fits.
You can print this using a 0.2 mm nozzle on a good calibrated printer, I used my Prusa MK4s, you want to use PETG for long term stability, resin might works too but I haven't tested the tollerances.
You will need two pins soldered at the bottom of the PCB, they need to be long enough to reach the Apple II PCB, then you need to cut the top part, under the Gateron switch, flush to the PCB (because otherwise the switch doesn't sit flush), I'm sure there are off the shelf SMD components that can be used for this, but I haven't got that far, after that solder the switch, press the stem in place and slide on the keyboard from the top making sure it's locked on the metal plate, solder and you are good to go!