This is a common tank arrangement for old tanks. Although it cannot be seen from this photo, this tank is only touching the bracket stand on three corners. When the person who disconnected the tank, cut the fill and vent pipes, the tank shifted on the stand. Fortunately the tank was not too full and it did not get bumped or moved, because the weight shift could have caused it to fall off the stand. The best opportunity for success is always to leave the tank in place and attached to all pipes until we, or another professional, can check for hazards.