There are schematics on the web of the connection that the optical sensor port on the flash body. One pair of pins is used to trigger the flash when the remote sensor cord is used.

So it should be possible to create an assembly that includes a peanut slave and a potentiometer that lets you set the strobe on manual and dial back it's output.

Or you could dial back using the standard sensor, and get a hot shoe slave. Wein makes a reasonable quality collection of them also.