Vintage steel + canti brakes = MTB drop bar conversion. Just pay attention to top tube length, many have crazy long TT which can make fit difficult. Typically, the earlier you go (think mid 1980s) the shorter the top tube.
Specialized Rock Combo. One of the early factory drop bar 26'rs. Rare and expensive, but cool.
My go to home made drop bar conversion, 1988 Schwinn Cimarron. Started as a deplorable garage sale bike. Slap wore out. Lots of touch up. Still my favorite! Latest iteration with a 1990 Deore XT transplant (from a donor bike). I have changed it some from this picture as I hated those S Curve calipers.