I’ll ask the Service Department for any info on dating the guitar from the serial number. The markings on the neck will presumably be internal notes from the factory and appear not to be written using Roman lettering.
It will likely be from 1987 when they appears in uk catalogs. The writing in back includes “604” which is the same as mine, model number Hohner arbor series 604. I tried to get rest of the Korean script translated to no avail.
All the ones I have seen start with serial number E7… which some suggest is eighty seven. They were made in Korea.
They are a nice guitar I’ve striped electronics, bridge and tuners from mine, which in hindsight prob wasn’t the right thing to do.