Vtg John Weitz Men Button Down LongSleeve Dress Shirt Sz 15 1/2-2 Single Stitch

Vintage John Weitz Men Button Down LongSleeve Dress Shirt Sz 15 1/2-2 Single Stitch. The color is cream/ivory/light beige? Please see photos for details. Embroidered initial on the pocket side I don’t understand the size it says 15 1/2- 2 - 20 RN 18760 Single stitch New never used but has a small like dark line on the center right side and black spot on the back left side sleeve see photos. Please check all photos attached carefully for further details and information. Please feel free to contact us if you have questions and concerns.