I don't think dwell meters ever were useful for setting up timing curves. They provided a much more accurate "dwell" (how long the points stayed closed) than setting by feeler gauge, but no real impact on timing curves.
As to dwell meters - EVERYBODY made 'em - usually in a dwell/tach handheld unit from Sears, Sun, Aquus, S-W, etc, etc. Prices used to range from about $19.00 to around a hundred or so.
The advent of breakerless ignitions consigned dwell tachs to the curiousity bin.
(one reason Chev -and GM in general - engines were more popular than FoMoCo, MoPar etc was because you could tune them easier by using a dwell tach on it while running) Ford & Mopar required you to shut it off, open the dizzy, reset the gap, start it up again and take another dwell reading. The GMs had that little window on the side of the cap that you stuck an Allen key into and adjusted to get the exact dwell while running.
However, the original poster was asking about "setting up timing curves", and a dwell tach won't do that.
Maybe an Oscilloscope?