The "E" does/did stand for electric.
I happen to own one I bought new in 1990 (Daddy's Junky Music, ordered from Guild $700 w/ hardshell case in 1990)...the only difference is your Guild logo on the head stock is printed, and mine is Pearl. The electronics in the 1990 D-25E were Fishman w/ active electronics supplied by a 9 volt battery which was mounted in front of the soundhole/ neck side. There was a tone (bass/ treble) knob, and a volume knob mounted on upper bout near the neck, and plugged in on the rear strap lock. There was no other strap lock, but I had one installed years later, hating to have a strap that tied off at the head stock.
The one I own is a natural spruce top, but was also offered as a brown stained top....kind of a country/ western look to it.