Field alterable, glass reinforced plastic door panel

A unitary door panel comprising a hinge side stile, a strike side stile, a pair of panel face sheets, and a cap strip, the stiles disposed parallel one to the other at the edges of said door panel, said face sheets spaced apart by said stiles, the hinge side stile disposed perpendicularly to said face sheets to form a closed panel edge, the strike side stile forming the other panel edge, said strike side stile comprising a channel in the shape of a three sided rectangle open to a side of the panel and extending continuously for the length of the panel, said channel having a base member and two channel walls, said base member extending between and disposed perpendicularly to said panel face sheets, said channel walls formed as thickened extensions of said face sheets, the depth of said channel being substantially less than the panel width, and said cap strip arranged to close said channel and form a finished door edge, said strip comprising a base and at least one projecting member, said member dimensioned such that it engagingly fits within said channel.