I've had these speakers for approximately two years now and they've been in dire need of restoration. Have not come around to it as they sound so darn good, and I didn't have any good substitutes to use while I put in the work until now.
I don't know everything about these speakers, but as far as I know these began their life in the JBL factory as the grey utility versions, they were then painted black with a blue baffle by Guido in Germany, but later left for Norway and was owned by Rolf. Rolf upgraded the speakers with what I think may be the charge coupled N3145 networks by 4313B on these forums. The networks were built by Guido. The crossover network does not have a passive section between the bass and mid, so they require active crossover. There was also an attempt to put American walnut veneer on the cabinets, but after some time the glue came loose and it has to be redone.
The drivers in these are 2235h for the lows and 2121H for the mid. Other than that they're stock with 2420 on a 2307 horn, and the wonderful 2405 for uhf. The 2308 lenses are also original JBL.
The idea is to restore the speakers into the beautiful walnut version. This is my first attempt at anything like this, so I'm sure there will be a lot of questions as the thread progresses. I also hope that people who see anything that doesn't seem right make some noise so I can correct it. I will spend a lot of time on this project as I want them to be in pristine condition when the job is done. These will be in my possession for the rest of my life and the thread can act as a fun resource for those who end up with them after me.
Pulled the veneer and getting ready to remove the crossover.
Closeup of one of the networks.
Removing the internal insulation and getting ready to remove the front trims and sand the whole thing down.