I need some help with replacing the original sappphire crystal of a SKX007 with an acrylic one. If the diameter of the sapphire crystal is 31.5mm as indicated on the parts number, then what size of a acrylic crystal will i need (not a trick question)? I'm looking at a thick high-dome acrylic crystal to resemble those vintage Rolex subs. I'll be grateful if somebody can point me to where I can get those too. Thanks guys in advance.