A kit for convenient repair patching of a panel whose access thereto is from only one side, such as in the situation of a drywall panel of a usual wall or ceiling. In various embodiments, a body member is provided with adequate support, by installation procedures wholly from the one accessible side of the panel, the body member itself providing a large area of the repair surface and/or providing a supportive body substantially bridging across the area of the hole to be repaired, and to which patching mastic may then be applied.