Baby Shoe Vase

Vintage blue pottery baby shoe marked USA. I've seen this piece attributed to Shawnee, McCoy, Brush and numerous other manufacturers, so I can't give a definitive identification. Pay special attention to the details, as there are many styles of the baby shoe vases from the same time period. It measures approximately 4 1/2 x 2 1/2 x 2 1/2 inches. There is no damage, but shows the normal anomalies of pottery pieces of the time. I need your zip code to calculate the postage.