This item is used on multiple models.
To replace the click tongue and button on models where it is peened into place, use a dremel drill with a fine tip to remove the old click tongue and click button. Then peen the new ones into place. Peening is when you gently tap the end of the click button with a small hammer until the metal spreads out enough to hold the click tongue in place.
On older 66, 67 and 68 reels a 36-60CH may be required. It measures .248 (roughly 1/4 inch) from just under the cap to the edge of the dropdown.
The 36-209 measures .283 (roughly 1/16 inch longer) Penn may have changed the 27-66 plate at some point, although there are no notes to that effect.
Any reel that uses the 36-209 can use:
36N-209 and a 69B-600 removable c clip
This newer style is held by the clip instead of being peened in place.