4c is a plan view taken along lines 24c-24c of FIG. 24b; FIG. 24d is a plan view taken along lines 24d-24d of FIG. 24b; FIG. 25a is a cross-sectional elevation of a modification of the casing molding and related components suitable for a new brick and molding installation;FIG. 25b is a cross-sectional elevation of a modified casing molding as shown in FIG. 25a; FIG. 25c is an end view of a mountin