Legacy versions of FileMaker Pro

I have a small, single user client who wants to run his fmp12 format version of a solution on a Mac that will only support up to FileMaker 16. This is to run standalone. He doesn't want the expense of upgrading his Mac and he has a Licence key, that he bought some time ago, for FM16. He no longer has the installer. Does anyone know where I can get hold of a legacy installer for him?

I sent you a PM.