Your memories are correct. The load-pole was pinned to the MGB and also to the leading edge of the hatch. The model may have a double sized hatch were the IFF lives, a hatch rarely seem open. The knuckle joint to permit swing is below the flloor soon after the lower pin. Nowadays there are bungies to limit swing and effectively stop a role change in flight from being possible. The hatch did concetina ala inverted 'V' to the stowed position just forward of the first bank of seats. In summary, as long as the load pole is vertical from the centre of the MGB, it is in the right place and if this means the hole is too large, it is an error in the model, even though there are a pair of doors in the floor at that point. The manual release is just above the floor mounting pin.