My leading candidate would be a 1984 Bridgestone 700 manufactured in 1983. Despite the similarity in colour scheme, the 1985 Bridgestone 400 came with exposed nut brake calipers and clamp style shift levers, while the OP's has recessed nut brake calipers and brazed-on bosses for the shift levers. The OP's bicycle is higher level but doesn't exhibit the high end features of the Grand Velo models. The frame level is consistent with a 600 or 700 but since the latter was partially spec'd with Superbe, that would my first choice. .