I don't need to see messages but I can tell you what the detective will tell you. You entered into a civil agreement for services and payment was engines you'll have to resolve the issue in small claims or civil court. I'm willing to bet Matt still has your engines if he's willing to ship them back. I also know he's about broke so would need money for the shipping because since you're asking for all your stuff back why would he pay to ship it back to you? That'd be like me paying someone money then asking them to pay $150 to return my money and the stuff they were supposed to work on.