for (mir=[0,1]) mirror([0,mir,0]) {
translate([0, basey/2 + sideslop, 0])
sheared_cube([lidx, sidewallt, bevelz], 0, bevelslope);
translate([0, basey/2 + sideslop + bevely, -tapethick])
cube([lidx, sidewallt, innerz + tapethick + lidt + zslop]);
for (mir=[0,1]) mirror([0,mir,0]) {
translate([0, basey/2 + sideslop, 0])
sheared_cube([lidx, sidewallt, bevelz], 0, bevelslope);
translate([0, basey/2 + sideslop + bevely, -tapethick])
cube([lidx, sidewallt, innerz + tapethick + lidt + zslop]);