I had not bothered to document anything as mundane as memory boards because they are simple and you can now buy 512K or memory chip for less than the cost of a DIN41612 connector.  512K in one chip is twice as much can be stored in this board.

Richard Marsh expressed an interest in these board for maintaining old systems so I decided to reverse-engineer them.

I put a faulty board on a hot plate and heat-gunned the components off the component side. I found the plastic sockets melted before the solder of the pins melted. The plastic left a hard black mess that was hard to remove. 

I tried soaking the board in acetone from Boots brand nail varnish remover. No luck. I wondered if its was far more diluted than industrial acetone so I added an old credit card as a test. That quickly reduced to a soft rubbery texture, then flimsy rubber that could be torn away to leave a coil of fine wire and the chip on metal contacts.

With hindsight I would have done it a slower but cleaner way, heating it from the solder solder and pulling turned-pins one-by-one.

I eventually removed all components and improved the visual track-to-PCB contrast by rubbing with abrasive rubber block. This removes the varnish from most tracks, leaving them bright copper on a green background.