One of the issues that people have with our worm sinkers is that it does not have a concave back. That is part of the reason we have not invested in other size options.
It is our belief that you can't make a 2 piece mold with hinges, a tight tolerance and with that shape and be able too be able to open the mold. You can't have a mold with a concave side, laying on its side and be able to make it work. I can see how the link attached works with the sinker cavity sitting vertical, but you also need to consider the two side swing on the hing and not pull directly apart. We have never seen that mold in person, so the cavity may be short enough that that the cast sinker in the mold does not interfere much when the mold is opened.
Their is a manufacturer than makes a 3 pieces hinged mold that works pretty slick.
