Antique Rare Item Saldorita1955 Swedish Mechanical Calculator

Saldorita is an "odd bird" among Swedish calculators, manufactured around 1937 by Saldoritaverken in Motala. The construction is somewhat reminiscent of the early pressing variants of Addo , however, the feed takes place via levers instead of with a stick. Saldorita was never a great success - maybe you understand why, when you try to follow the following ...
INSTRUCTIONS FOR USE FOR THE "SALDORITA" CALCULATOR
Control: Before each new count, the zero button is pulled out slightly, turned to the right to the home position, the total button is pressed and the control strip must then register zero. The zero knob must not be turned until all the keys are in the bottom position. All counting is from the left.
Addition: The keys are postponed to the desired number position and must not exceed the line , the number is registered on the strip by means of the total key, the keys return by pressing the return key. In the same way, number after number is carried out, after which the final sum is obtained by pressing the total button. Each number does not need to be recorded, thereby saving significant amounts of paper.
Subtraction: The return button is placed in the center position (6), the keys are raised, the return button is transferred to the subtraction position (7), the number is registered, the keys are pulled down to zero, one at a time starting from the left, while the respective round metal buttons (4) is pressed and the total is registered with the total button.
Correction: If the key is moved too high incorrectly, for example to 5 in st. f. 4, the subtr. button must be used. By simply pulling back the key, 5 will be registered in the counter but 4 on the paper strip and thus errors will occur. Correction takes place by transferring the return button in subtr. Position, incorrect key is pulled down in the correct number position, the return button returns and the number is corrected.