"...being predictive, being right about the future, is not the point of any given story or novel. The point is about exploring as wide a range of possibilities as possible."
- Peter Watts

Appropriately, Lazarus Long, eldest member of the Howard Families, uses the traditional weapon rather than the new-fangled version.

These quotes are taken from the expanded versions of these stories from the collection The Past Through Tomorrow; both of these stories were expanded from their initial publication in 1940 and 1941.

The same weapon is mentioned in Coventry published in 1940:

Alec broke ranks and backed up to the wall, screaming, “You can’t do this to me! I won’t go!” His deadly little vibrator was exposed in his hand, and the right side of his face was drawn up in a spastic wink that left his teeth bare.

“Get him, Steeves,” ordered the corporal. The private stepped forward, but stopped when Alec brandished the vibrator at him. He had no desire to have a vibroblade between his ribs, and there was no doubt as to the uncontrolled dangerousness of his hysterical opponent.

For purposes of comparison, Randall Garrett wrote this about the vibroblade in his 1962 novel Unwise Child:

A vibroblade is a nasty weapon. Originally designed as a surgeon's tool, its special steel blade moves in and out of the heavy hilt at speeds from two hundred to two thousand vibrations per second, depending on the size and the use to which it is being put. Make it eight inches long, add serrated, diamond-pointed teeth, and you have the man-killing vibroblade. Its danger is in its power; that shivering blade can cut through flesh, cartilage and bone with almost no effort.