I've always preferred the look of tulip buttons. If anyone is interested the CE tuner buttons are a straight swap with Kluson® Replacement Keystone Buttons For Revolution Tuning Machines that I found
Tone Ninja Tintul wood Tulip Tuner Buttons (6) fits most Tone Ninja and Kluson tuners | SportHiTech
Kluson Firebird Banjo Metal Keystone tuner buttons w screws & washers KFBKBC | Reverb
TK-7711-000 Plastic Keystone Buttons for Vintage Keys (Qty 6) — Allparts Music
Amazon.com: WILKINSON Black with Black Button 3x3 Deluxe Vintage Tuners Guitar Tuning Keys Machine Heads with Plastic Keystone Buttons for Les Paul/SG/ES, (K1949) : Musical Instruments
NEW - Plastic "Single Loop" Keystone Buttons (6) For Vintage Style Tuners | eBay
CHROME KEYSTONE 3+3 TUNERS
Kluson Replacement Button Set For Revolution Series and Plus Series Tuning Machines
Gotoh Tuning Machine Buttons
Grover Keystone Button
NEW Grover 106 Original Locking Rotomatic Tuners Keystone Buttons 3x3 – GUITAR HEY
Grover Keystone Button
TK-7722-002 Set of 6 Grover Gold Keystone Buttons For Rotomatic Series Tuners | Reverb
NEW (6) Keystone Buttons w/ Screws for Grover Rotomatic Tuners Keys - NICKEL | eBay
Kluson Replacement Button Set For Vintage Diecast Series Reissue Firebird/Banjo Tuning Machines
NEW - (6) Keystone Tuners Buttons & Screws for Gotoh Machine Heads - GOLD #04 | Reverb