Like Dave I would fit at least some spacers with flexible washers.
This joint will flex, and if bolted up too tightly will damage the end plate of the front wing and the face of the rear wing. The early cars (like yours) have only a narrow gap which does not allow the thicker rubber washers of the late cars, so fit the thickest depth washer you can insert and bolt up quite loosely (but with nyloc nuts to ensure they don't come undone)
