A good friend found a company that sells victorian style workmens clothing. The clothing they sell is not intended for re-enactment. The coat he bought had zippers and plastic buttons. So my husband and I made some alterations.
We removed the zippers and added leather pocket welts. The plastic buttons where replaced with blue (they look lighter in the picture) wooden buttons. The buttons are from 1910.
The coat he bought looks a lot like an original pattern from 1877, sold by Ageless Patterns.