A curing assembly for forming an integrated composite component comprising a composite component preform formed of curable resin fiber-reinforced plies and a curing caul covering the component preform, wherein the composite component preform comprises: (i) a base panel formed of curable resin fiber-reinforced plies; (ii) a pair of mirror image opposed L-shaped stringers (42a, 42b) formed of curable resin fiber-reinforced plies and having respective opposed lower leg sections having opposed lateral edges positioned adjacent the base panel and upper edges of the stringers extending upwardly from the base panel, and (iii) a pair of mirror image curing mandrels (44a, 44b) having downwardly and outwardly inclined exterior surfaces; and wherein the curing caul comprises a one-piece three-dimensional resiliently shape-retentive fiber-reinforced body comprised of a fibrous sheet embedded within at least one layer of a cured elastomeric resin, wherein the elastomeric resin is a room temperature vulcanizing silicone rubber having a coefficient of thermal expansion when cured of at least 1.0 x 10 -4 /°C, and wherein the shape-retentive fiber-reinforced body includes: (i) a stiffened perimetral edge region adapted for placement against the base panel of the composite component preform; (ii) a stiffened ridge region vertically spaced from the stiffened perimetrical edge region adapted for placement against the upper edges of the L-shaped stringers; and (iii) a pair of opposed resiliently compliant sides extending downwardly and outwardly between the stiffened ridge region and the perimetrical edge region, wherein the compliant sides are positioned against the downwardly and outwardly inclined exterior surface of the forming mandrels (44a, 44b) and against the opposed lateral edges of the lower leg sections of the opposed L-shaped stringers (42a, 42b), and wherein the elastomeric resin of the shape-retentive fiber-reinforced body undergoes volume expansion during high temperature curing of the composite component to exert sufficient additional pressure against the composite component preform during curing. the composite component preform comprises: (i) a base panel formed of curable resin fiber-reinforced plies; (ii) a pair of mirror image opposed L-shaped stringers (42a, 42b) formed of curable resin fiber-reinforced plies and having respective opposed lower leg sections having opposed lateral edges positioned adjacent the base panel and upper edges of the stringers extending upwardly from the base panel, and (iii) a pair of mirror image curing mandrels (44a, 44b) having downwardly and outwardly inclined exterior surfaces; and wherein (i) a base panel formed of curable resin fiber-reinforced plies; (ii) a pair of mirror image opposed L-shaped stringers (42a, 42b) formed of curable resin fiber-reinforced plies and having respective opposed lower leg sections having opposed lateral edges positioned adjacent the base panel and upper edges of the stringers extending upwardly from the base panel, and (iii) a pair of mirror image curing mandrels (44a, 44b) having downwardly and outwardly inclined exterior surfaces; and wherein the curing caul comprises a one-piece three-dimensional resiliently shape-retentive fiber-reinforced body comprised of a fibrous sheet embedded within at least one layer of a cured elastomeric resin, wherein the elastomeric resin is a room temperature vulcanizing silicone rubber having a coefficient of thermal expansion when cured of at least 1.0 x 10 -4 /°C, and wherein the shape-retentive fiber-reinforced body includes: (i) a stiffened perimetral edge region adapted for placement against the base panel of the composite component preform; (ii) a stiffened ridge region vertically spaced from the stiffened perimetrical edge region adapted for placement against the upper edges of the L-shaped stringers; and (iii) a pair of opposed resiliently compliant sides extending downwardly and outwardly between the stiffened ridge region and the perimetrical edge region, wherein the compliant sides are positioned against the downwardly and outwardly inclined exterior surface of the forming mandrels (44a, 44b) and against the opposed lateral edges of the lower leg sections of the opposed L-shaped stringers (42a, 42b), and wherein the elastomeric resin of the shape-retentive fiber-reinforced body undergoes volume expansion during high temperature curing of the composite component to exert sufficient additional pressure against the composite component preform during curing. (i) a stiffened perimetral edge region adapted for placement against the base panel of the composite component preform; (ii) a stiffened ridge region vertically spaced from the stiffened perimetrical edge region adapted for placement against the upper edges of the L-shaped stringers; and (iii) a pair of opposed resiliently compliant sides extending downwardly and outwardly between the stiffened ridge region and the perimetrical edge region, wherein the compliant sides are positioned against the downwardly and outwardly inclined exterior surface of the forming mandrels (44a, 44b) and against the opposed lateral edges of the lower leg sections of the opposed L-shaped stringers (42a, 42b), and wherein the elastomeric resin of the shape-retentive fiber-reinforced body undergoes volume expansion during high temperature curing of the composite component to exert sufficient additional pressure against the composite component preform during curing.