"supposed to be used with light from a light bulb" Just not true and everybody back then knew to use a neon or line synced fluorescent. Many tables, Sony, Dual and others, had built in neons that illuminated the strobe on the edge or under the platter. I don't know about the TD-115, and can't tell from what's on line, but there were a variety of small bayonet neons and other weird bulbs that looked like a regular bulb, but weren't. I'm guessing it took something like that, or a special bulb with a short time constant filament. I'll throw in a plug for my free alignment template generator. It not only does alignment templates for any table, but can print strobe discs that are better than any downloaded image file because they're generated on the spot for whatever resolution your printer supports.
On technology, as an old fart who likes things built like a tank, I'd have to say that modern phones are probably one of the best built and most robust things people today own. Sure, tech advances and you replace them for that reason, or because you dropped it in a puddle, but the designs are excellent. Well, save for sealing. Most everything today is crap. Look at dehumidifiers and major appliances. They used to go for 30 years and now you're lucky to get 7. Who can afford that? My HP Laserjet 5p is still going strong at 24 years old. How long can you get out of a modern inkjet? I routinely use electronic test equipment that's 60 years old and can still get parts and fix it. Try that with any modern uP based contraption. Those old turntables stack up pretty well!
