The neck plate has been replaced with a FCGR 2mm sustain-plate so we need the clues from the innards to declare this as a December 1978 build, and it is the spec that appeared in the 1979 brochure. Does that plate work? We can't say it doesn't, but with an already high bar set by the Excel pick-ups, it is just accentuating already great sounds. Better is better - on it stays.
 
Having a small headstock on a Greco is usually the preserve of the SE-800s, all of the lower order models conformed to the contemporary fashion of large headstocks. The neck has a full profile and a slight V-feel around the skunk stripe. A 7.25 radius and (according to previous owner) a recent refret by FCGR make the guitar feel a lot more expensive than it is. FCGR also added Grover Deluxe tuners too.
 
The other notable change to the guitar is the mid-blend (aka Hendrix Mod) which re-assigns the lower tone control to a middle pick-up fader duty allowing a massive array of tones from the simple 3-way arrangement.
 
The result is a fantastic looking guitar with genuinely sensational sounds. These Excel pick-ups are revered by many experienced players - never too hot, never too thin, always in the sweet-spot, and now set free to work together in even more useful ways. As always, have a listen to it on the video. If you are free of the "has to be a Fender" constraints, and want a high performance guitar without spending a fortune, this should be a consideration.