Thanks for the input; I have a bit more information.
1) The EASA MEP Rating has expired. (For American pilots unfamiliar with European flying, unlike the US where a single flight review covers "everything," in Europe "everything" has to be renewed individually or it expires individually. The license remains valid, but the authority to fly something specific like "single engine piston" or "multi-engine piston" can go away despite over things being current. The various ratings like SEP or MEP can be renewed or extended by currency or with an examiner.)
Apparently, having an FAA ME rating will allow my friend to renew his EASA MEP rating with just a check ride w/o dual.
2) He's aware that he can use his existing European ATP towards an FAA ATP. Not sure what his plans are for that.
Thanks again. I'm always impressed by the extant of knowledge here
Terry