i have two sherwood rona masks and love them. but the left buckle on one broke off the silicone "knob" it was attached to. it seems like a simple pin conects the buckle to the mask, and it should be easily replaceable ... but my local sherwood dealer (Tom's Dive & Swim - Central Texas Source for Scuba Vacations, Gear and Lessons) says it can't be replaced. is this true? can i order another rona mask strap w/ attached buckles directly from sherwood, or a 3rd party strap w/ buckles that will fit the silicone knobs & pins? i'll be diving my backup mask until then. thanks.