Weighted Engineer's Pen Cup

My father asked if I could make a cup to hold a single pen or 2. He wanted it weighted and conical. When I whipped this up for him, he said "That's just like the one I had on my drafting table in the 70's!".
Bottom of cup is open to take a 51mm OD, 21mm ID, 3mm thick washer. It's probably imperial sized, but I didn't bother measuring.