Yes. See Sheldon's handlebar sheet. Non-drop bars are commonly 22.2mm in the grip area, but drop bars for road bikes have almost always been built 23.8mm almost everywhere.

Here's my '79 Fuji from when I had it set up with cork tape:



And here's my '83 Miyata, shown here fitted with the same model of handlebar, but with cotton cloth:



Also, while I don't think I've installed vintage levers onto new bars, I have done the reverse a couple times. In each case, the lever clamps fit just as precisely on the forty-ish-year-old handlebars as they do on new handlebars.


What specific handlebar model? On modern drop bars, sometimes the "grip area" doesn't start until the ramps. This is obviously the case on bars with "aero" tops, but it's sometimes true for bars with round or round-ish tops as well. If you're checking at the tops rather than the drops, this can explain discrepancies.