What are these holes for?

While working on my 1303 and removing the rear wings I noticed two holes with captive studs behind the damper top mounts.

I am wondering what they are meant for. The offside one is offset to the rear.
By the look of them they may have never been used.

Z bar mounting points

Thanks! Further reading tells me that they were used on the '67 and '68 swing axle models with a softer torsion bar setup to give a more “luxurious” ride.