I found my old chemistry set when we cleaned out my Dad's house a couple of years ago. I had several; this was the last, a big double metal folding box of goodies. Never found my old Radio Shack (Tandy) electronics kit, though. The later ones went to the white perf strips or whatever you call them. You can still get those today (electronic kits), not sure about chemistry kits.
Re. LDR as volume controls: I wish I had kept my old measurement data -- most of my early notes were lost in a move (small truck filled with papers and such crashed, I think, and we lost most everything in it -- insurance covered the "value" but not the memories and much was irreplaceable). It was noisy and not terribly stable. I made a fancy regulated supply (fairly new thing then) for the light source, and was working on a feedback loop to control intensity that helped, but ultimately decided it was not worth it. A couple of manufacturers used them, briefly, with nice marketing to match, but they only lasted a year or so before being replaced by stepped attenuators and such. It was years later I learned the films used were intrinsically noisier than standard resistor materials, and some of them had fairly high voltage coefficients as well so would modulate with signal.