Broken smokestack, and overall rough condition. Sloppy paint, possibly touched-up?
Other differences from Holgate #54 "Holgate Ferry", Educational Play Materials:
* Four nails for each of the two small square roofs, instead of 2.
* Smokestacks are black with red, instead of yellow with red and black.
* Floor is darker
* Large flat-head (roofing) nail in center of roof, instead of one of the rounded studs used elsewhere.
* Main roof is slightly thinner, appears to be plywood, and is partially painted on the underside. Roof appears to be painted post-construction (see earlier comment about touch-ups), and nails are painted over.
* Contour of hull is slightly different.