Re: RG321MH Bridge Saddle Height Screws
I have the mahogany oil finish RG321MH and had the same problems with the screws in the bridge. You can get them online, on websites like ebay, mcmaster-carr and others.
They are called M3x10mm Set Screws, they use a 1.5mm (metric) allen/hex driver to set height. I tried using the M3x8mm set screws and they were just a tad to short on the D and G strings, so M3x12 mights just barely stick out on super low action setups. I was fine with plain set screws but the matching stock type were black oxide finish.
Sadly, this was the only physical flaw holding this Ibanez model back, each set screw was a random length between 13mm up to 17mm on mine and 11.5mm was max needed.