Pair Vintage Dietzgen 12" Triangular Scale Drafting Rulers 31636 & 41631M USA

Pair of vintage wooden drafting / engineering rulers by Dietzgen. One is model 31636 and the other is model 41631M. Both rulers are 12" long and have 3 sides. The 41631M model has wear including some rough spots along the edges and minor paint loss. The wear on the 31636 model is minor but there is a stain on one of the sides of the ruler. See pictures for further details on condition.