I see a set of all four chrome cased testers (model 27-14 Cam Angle/ model 27-15 Ignition Tester/model 27-16 Tachometer/ model 27-17 Volt-Amp ...) on eBay. I only need the one tester which is the model 27-15 to complete my partial set. I don't imagine anyone selling these on eBay would want to...