I think you're nuts to try and copy one.
When the piston goes up, creating the vacuum which pull the coffee down and leaves the grounds above, the piston rod (if you want to call it that) looks to be submerged in brewed coffee. Unless I'm not seeing something. That means your threaded actuator won't work.
The water temp off the boiler is PID'd. You could cannibalize an espresso machine for that, and PID it, leaving the pump intact. If you don't add a PID, then you're missing out on one of the Clover's selling points of being able to control water temp, and you may as well stick to a french press.
The valve and solenoid that closes to produce the vacuum and opens to push the brewed coffee to the spigot would be difficult.
I'd never say it couldn't be done. If someone has the tooling, money and patience, anything's possible. But for an amateur to attempt it... press pot, vacpot, or aeropress come close enough for me.
Nothing would delight me more than to be proven wrong on this.
