Looking at that RCtarget....
The base unit:
The timer:
https://www.ebay.com/itm/12V-Thermos...-/401229762943
The RPM meter
https://nl.aliexpress.com/item/Digital-LED-Punch-Tachometer-RPM-Speed-Panel-Meter-4-digit-9999RPM-Tacho-Gauge-Hall-Proximity-Sensor/32671761984.html
I think on the inside a normal brushed motor is used with an el cheapo PWM controler
OK, nice looking case which is not that difficult to make fittin on the top cover of the mini deep fryer.
With outsourcing the bending and CNC milling of the materials I do not think the total costs will go above 350 dollar. I think they can share some fee with me for the idea