Manufactured for Sears by Kamerawerke Wilhelm Witt, this rangefinder was a great value (even compared to the Argus C-4) when it was introduced in 1958.

The 51 has a two-piece wind lever on the top left, counter intuitive film loading and moderately helpful instructions on the bottom. Also sold as the Iloca Rapid B.
Manual from Butkus.org

Make Tower (Sears)
Model 51 (1958a)
Year 1958
Format 35mm
Shutter Prontor-SVS
Speed B, 1 – 1/300
Lens Steinheil Munchen Cassar
f2.8 50mm
Focus 3ft to ∞
Aperture f2.8 – f22
Light Meter No
Rangefinder Yes, Coupled