Brazil made slide rule.

Data:

• Made by the Brazilian factory of technical drawing materials Arquimedes.
• “Sistema de Medeiros”
• Pat. Pend. Term. N. 41833.
• No cursor.
• No documentation.

Questions:

1. What should the cursor look like, so it can be reconstructed?
   
2. What is this? How to use it?
   
     Source: A Noite Ilustrada 1948-07-20 p.35
   
     Source: A Noite Ilustrada 1948-08-10 p.21
   Google Translation:
   The slide rule for scales
   "De Medeiros" System
   Practically applicable to solve quickly and with absolute precision problems related to graphic scales. It facilitates the creation of plans, maps, sketches, readings of quantities on scales, transposition of scales, etc. It includes the fundamental logarithmic scales for solving multiplications, divisions, successive multiplications, multiplications combined with divisions, proportions, simple and compound rules of three, percentages, squares, square roots, cubes, cubic roots, fourths and sixths, extraction of common and natural logarithms, calculation of whole or fractional powers, areas of circles, volumes of cylinders, perimeters and areas of flat figures, areas and volumes of solids, conversion of measurements, etc. It has the following scales: graphic: 1:20, 1:25, 1:33 1/3, 1:50, 1:75, 1:100, 1:125, 1:150, 1:200, 1:300, 1:400, 1:500 and all those that are multiples or submultiples of these; logarithmic: L, A, C, D, K; an inch scale (a) with a beveled edge, and a triple-decimeter graduated in 1/2 mm increments. — It also has a wide-view cursor, equipped with a pointer, with three reference lines; two fasteners for the compass and a side fastener for the tongue.
   Manufactured by Arquimedes
   Unique price throughout Brazil: CR$ 450.00 — With case and instruction book.
       Resellers accepted in the states
   Orders by Postal Refund to: J. Medeiros Jor.
   Caixa Postal, 111 — Rio de Janeiro Andries de Man