That must have been pretty scary, Pace. I am pleased you were still looking out and saw the glider. Did he see you? can you give a reference to the report?
Gliders, I believe, were still flying in those days - relying on the odds of two aircraft colliding in uncontrolled airspace....the records show it has hardly ever happened. Most midairs happen in the circuit, it seems. Most of my frights have been over active airfields in VMC.
So very few pilots were bold enough to fly in cloud. Or at night. So both are much safer than flying in the circuit in VMC......
Nowadays nervous glider pilots invest in Flarm. I am told it works very well, if the other aircraft has it.