I’ve found a source for the grommets that attach between the quarterlight window button and the latch on Tiger and Alpine Series 3, 4 & 5 hardtops with the small button.
Britech Industries Stock Number 2854 fits as one piece. It goes in by fingers and fingernails with a little work. Enlarging the diameter of the hole in the plexi just a tiny bit would help the install, but is not necessary. Once the grommet is in, a little WD-40 on the button shaft would help get it thru the grommet.
Britech Industries’ phone number is: (772)286-9278.