On a regular basis - my daily driver saddle. It's a custom Crawley that my mom had made 30 some years ago. (I have 2 of the exact same saddle - one with chrome, one without - they are permanent fixtures. Love them!) I also occasionally ride my grandfather's old Hereford that is an early 50s model.
Now if you'd said "equipment" instead of tack it would have been my tractor, it's a '59 Ford 861 Powermaster.