I just ordered one for my 71 GTV. Some keyrings have the option to customize leather color. These pre-date your '89 but the quality is great and better than purchasing something from recent years (IMO).
RaceQuip PRO 15 Helmet SA2015 Approved size L (59 - 60 cm)
Only worn twice. Certification date is 2017/07
Visor still has protective film.
One of visor screws is non-original but is fully functional
$70 + shipping