Very interesting.  My cousins who were much older had one of those RCA 45 players, but I never saw it in use.  Even back then I thought a limited use item like that wasn't practical.

I remember when I was younger, a friend and I became interested in collecting 78s and he found a very early 20th century Columbia demonstration record for their "Double Disc" system, where both sides of the record could be played instead of just one.  A portion of the narrative was, ". . . Double everything except price!"

It seems that Columbia was ahead of Victor with introduction of new technologies.  I tend to prefer their early "Viva-Tonal" electrical recording process over that of Victor's "Orthophonic" method, but am not sure which came first.  I know that by 1927, both companies had switched to the electrical process, and both of them redesigned their labels to reflect it.

I haven't watched the video, but I'm aware of the format war. I remember reading this when I was teenager. I'm not sure of this point, but it's very possible, given an interest in audio--and the fact that I remained an analog diehard--that I've seen the discussion of this format war discussed since then.

Past this, I've been told my grandparents had what must certainly have been a RCA 45 RPM changer.

Also, RCA's 45 changer is the only one I've ever seen where the whole spindle revolves along with the stack of records that it's holding, but I kind of like it!  This would explain why RCA designed the 45s to have a shoulder that would keep them from making contact with each other when stacked.

One thing I'm not sure about.  Did RCA use the same colors for labels after they stopped making the discs in various colors?  I know I've come across RCA 45s with labels in red, blue and green on black vinyl, but can't recall ever seeing them with yellow or a lighter shade of blue.  I've also only seen red vinyl RCA 45s in my thrift store searches.  The other colors must be fairly rare.

78s have interested me, although it's one of those things I've never gotten around to doing seriously. I recall playing a bit with 78s when a teenager, but under less than optimal conditions--although truly optimal (special electronics, a variety of cartridges or styli to accommodate different groove geometries and record wear, etc) probably makes 78 RPM records a money pit of a hobby ...

I have always had a weakness for old/obsolete technology, and then there an argument for 78s having material that will never be released again (although in some cases that might be a good thing), or, if released, it may be overly processed. (I remember one letter to an editor talking about his original 78 having more life than the heavily processed, noise reduced CD reissue.)

Plus I amused myself for years thinking that being active with 78s could be fun when people started in on: "Why do you play LPs? They are obsolete." I could then say: "If you want real obsolete, look over there at the 78s!"