Timing Chain Mounting Bracket

We recently opened the valve covers of a '70 4.2 E-Type and found two pieces missing from the ears of the timing chain mounting bracket. The pieces would have closed an area wich holds the cam, but are now open like slanted U's. We do not believe this was a recent break as there is no evidence of the missing pieces within the engine. Anybody know how important these are? The cam rides inside but well away from missing piece.