We used to open up the sealed can on a vibrator and dress up the points when they got funky and the thing quit buzzing. That's probably the limiting factor- - - -whatever current the points can handle without burning. They're probably not as rugged as distributor points, as I remember them being about half the size of ignition points, and ignition points get toasty at about 5 amps. I'd guesstimate a vibrator might handle 2 1/2 - 3 amps maximum, probably less if you want to have long term survival. A vibrator's original purpose was to create a DC square wave which could be transformed like AC up to a much higher voltage for use with vacuum tubes. That process didn't involve much current across the points.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!