yamaha old apx series - saddle.nut and bridge pins material??

[Tiffaob]

Hi I was just wondering wether anyone on the forums knows what material the saddle, nut and bridge pins are made of on the old Yamaha apx series (I own an apx-7A) as I was thinking of upgrading them if they are plain plastic , I've had the guitar for around 12 years and it's a beaut! Thanks guys !!