http://www.rechnerlexikon.de/artikel/Mercedes_Euklid_29

http://www.rechnerlexikon.de/artikel/Mercedes_Euklid_Geschichte

The machine seems working perfectly on arrival.

After a few tries the carriage was blocking sometimes. This appears to be a problem of wear out of the carriage transport / shift mechanism. About 0.5 mm in total was missing on the catch top. This catch directly controls the shift stop of the carriage in all positions. I have bent a 0.5 mm plate of steel and mount it on top of the catch to get the carriage stop on the right positions. This works (see pictures). The alignment catch (right above the L key and under the display cap) which checks the carriage position before turning anything, is now always perfectly aligned with the carriage. Problem solved.
It seem to me that this material of both the catch and the distance plate has some room for improvement in design (steel sort which is slightly stronger). The tuning of the right position is very critical for the performance / run smoothly of the complete calculator. But after perhaps so many years I better stop criticizing.

In certain positions of the carriage it was not possible to set the swing counter to plus. The problem was a loosen hinges of the connection to the carriage transport / shift mechanism.

One key one of the 7th keyboard unit was defect. It appears a problem of the nine case. This was inclined and therefore holding the zero plate and prevent catching the one key.. Dismantling that unit and bending the nine key house in shape and the one plate could pass, and was working again.

(auto divide is not tested yet).