Early Monte Carlo (Three Buttons)
Earliest Version
The earliest version has the “fishtail” on the minute hand; “Auto-Rallye” printed above the Heuer shield and “Monte Carlo” printed in script; and “Pat. Appl. For” above the date window
Later Version
“Fishtail” minute had is replaced with standard version of the minute hand
Standard Version
dial marked “Pat. Appl. For”;
Later Version -- Dial Marked "Patent"
dial marked “Patent”
Latest Version (Dial Marked for Tritium)
dial marked “Patent” and for tritium (T<25 mc)