ScubaPro50, I probably come from the same era as you and I definitly remember the time when you were a USD guy or a Voit guy or a Healthways guy etc. Almost all of every divers equipment came from the same brand. I mostly used USD. This was pre 1970, I was a kid and impressionable but most older divers I knew at that time were the same way. My instructor used USD gear and because he was influential upon me I ran down to the dive/hardware store with all my piggybank money and bought USD gear. I also had a Nemrod set, Nemrod regulator, backpack, orange Nemrod tank, knife, the whole set. My USD set was the same way. Every single piece was USD, depth guage, knife, tank, regulator, every bit. This was pre BC era, pre octa era and one of my USD regulators was a double hose Mistral. The only thing that was not USD or Nemrod in my sets was my Voit A66 Viking fins.
In the 70s as USD gear became junky and Voit went away I began buying whatever I liked without regard to brand matching. Now I am partial to Mares, Mares fins, Mares X mask, Mares regulators etc but everything else is a mix.
When I vintage dive I try to stay all USD but my main backup regulator is a Voit MR12 and if I use a BC it is my vintage Dacor Seachute so despite my wish to stay authentic I have failed. Well, I could get in the water 100% USD as long as I go no BC, my last USD horsecollar gave up years ago. It is very diffucult to go modern or vintage and stay in one brand of gear. N