Mamiya Sekor C f/3,7 80mm for TLR cameras

Please,

can somebody give me information about Mamiya Sekor f/3,7 80mm for Mamiya TLR cameras. I recently bought one in like new conditon. This was cheaper than prime lens f/2.8 80mm and it be placed shor time as set lens with Mamiya C 220 bodies. I cannot find any serious information about this lens. Does anyone know the optical design? It is Tessar type? Can anyone compare it with normal f2, 8 80 mm (sharpness, etc.)?

Thanks

Krystof

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