Here are the documents regarding the orders of the Thuring boards.
This the design of the main MST-13 board.
Here is a good quality pic of the board design:
1st order
Ordered on 13 August 1985
20 ordered, 24 delivered on 3 September 1985
“solder masked” on one side [Lötstopp eins.(eitig)]
No bore holes
“Tin” plated
2nd order
Ordered on 9 October 1985
35 ordered, 34 delivered on 12 November 1985
“solder masked” on both side [Lötstopp doppelseitig)]
3 x Fenster Fräsen (Mill three windows)
No bore holes
“Tin” plated
Comments:
Notice the now infamous “ZINN” . (To tin)
However, in this technical field, neither “Zinn” nor “Tin” means tin. It is just slang for the process and does not tell anything about the material itself. In the case of these Thuring boards, it is actually a mix of Lead and Tin. This is absolutely crucial to this case.
PT35B 