I'm about 99% sure Testors and Tamiya lacquers are the same formula. So you won't have problems. And, if enamel is 100% cured, you CAN get away with very thin coats of Testors/Tamiya lacquers over them. Testors Dullcote and Glosscote are "lacquers" and I've been using them
over cured enamels for years. It works, but do not apply heavy coats!