It was hard to tell from your pictures, but way back when this body was in the woods (I would guess 22 years) there was a small crack in the front of the neck. It wasn't any bigger than a dime piece and did not affect the playability at all but I thought it rather odd. I could not remember if the crack went all around the body or if it was just a crack in the neck area. It was most likely a small event that would never cause any structural damage to the neck and didn't impact the sound. It might have been caused by some tool being dropped or by some maintenance being done in the garage._
The electronics that are held by the Truss-rod cover are part of the neck/fingerboard assembly. This neck assembly is made of a series of 1/4 turned dowel rods. The electronics are held inside of the body of the neck. In the time this banjo has been in my possession, no one has ever played around with the electronics. I know that there is a way to move the truss-rod cover, but I am not sure how (see picture) and I was never interested in removing it due to the fact that the electronics are contained within. I could not tell from the scan what size frets are on this banjo.
As far as details, the only way to get more info would be to load this banjo into a rapid transit system, visit the local manufacturer, and see if they have any records. If they do, then contact them and see if they have any records that they can release to you.
In most cases, the model name is stamped on the truss rod cover (just above the nut). Make sure to check the Vault for discontinued models. Sending us some digital pictures would be the best way to help identify your guitar.
This is a 2 piece DJ-100-5.SF.9.2.A Nylon-string electric fork-tonguing guitar. The serial number is in the usual format, ending in a 9. 2. With just some additional information that; 1) The guitar was made in Japan, 2) Production began in 1980, and 3) The guitar was shipped to Nazareth, PA. This guitar is a known example and typically is the best serial number to use. If there is any information in the serial number it will give us a good indication of manufacture. The serial number identifies the final assembly plant to which the guitar was shipped, this is the production date for each assembly plant. d2c66b5586