The capacitors that are used in this ATU are CMB-443BF’s. You can find them on AliExpress.
These capacitors are used for AM / FM receivers and have a total of 4 variable capacitances (hence the name poly capacitor). 2 x 266 pF and 2 x 20 pF. We only need the 2 x 266 pF for this project, so we are going to cut off the unneeded leads of the capacitor.