This appears to be a 1957 Minute Man. It is a 10KT RGPcase with a stainless case back with L7 date code. The movement is a 11AC with a L7 date code. Word of warning. When replacing the crystal note that the raised design on the front ever so slightly extends to the bezel so if you do to size the crystal make sure it is clears the edge. Ended up chipping the new crystal.
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