1977 Takamine F-312. Your search ends here if you're looking for a silk steel set of low tension strings to not pull the bridge up on your old guitar. They maintain that bright highs and deep lows while handling like electric guitar strings. You can get your bends in with these strings unlike with nylon strings. They also have that will wrapping at the end to protect your bridge from getting chewed up. I've been using these strings for years, its was hard tracking them down through the new packaging but these are the lightest all non nylon strings that Martin makes. If you want lower tension than this without going nylon, you will have to build your own custom set. If you want nylon for lower tension go with the m160 or the m260 classical from Martin. They have a tension rating of 88 for the tie (m160) end and 85 for the ball end (m260) took me a week to find this knowledge with everything shut down due to the pandemic. Thought I'd save you some valuable time.
I have used these strings for many years. The quality and sound is outstanding. The strings are silk wrapped at the ball end for extended life. The nylon core on the wound strings lessens the tension a bit which I like. The sound is not as bright as bronze wound strings but it is fine. They hold lowered tunings well and are easier on my fingers. I play finger-style a lot and these are perfect for that.
Great strings for beginners. You can double your playing time with these low-tension strings and honestly, they sound almost just as good as phosphor bronze.