Many thanks to Russ, AD0QH for his feedback and photo showing how his matchbox is installed. This is probably the best way I have seen to relieve strain on the studs and I have included this in the updated operating instructions. You can get the cable thimble and clamps pretty much anywhere such things are sold. Russ got his at Home Depot and notes that you can also order them online for around $2.00 per set.
73 de Ken W4KGH