When I bought a used tank at my lfs
, there was an issue with the center brace, it was cracked. The top unit is one molded piece, you can actually just purchase the entire piece which includes the center brace. I would not trust repairing it with silicone, but that's just personal preference.
75: blood parrots, featherfin cat, emperor tetras, turquoise rainbowfish, BN plecos, japanese trapdoor; 46: WCMM, gold inca snails, ghost, bamboo & amano shrimp, kuhli loaches, rummynose & ember tetras, endlers, platies, flame gourami, guppies; 16: pygmy, peppered, loxozonus corys, otos, assassins, RCS ... ~ Research PRIOR to purchase.... ~