Campagnolo used 3/16" ball bearings in their bottom brackets 3 times.
Once in the early 60's, the outside of the cups will be stamped 3/16 but this is before the reverse internal rifle in the cups.
Next was with Super Record. The cups were alloy with pressed in races. They have the internal rifling. Mated up with the ti spindles of two different designs, initially hollow and later solid with threaded ends. two basic lengths, 113 and 115 mm.
Last was Corsa Record, cups the same as Super Record but the spindle was steel. Spindle lengths were short to mate with the C Record crank arm design.
Not sure what you have, but there is not a great deal of acceptable cross-era crank arm compatibility. I suggest you use it with what it was designed to work with, or sell it off, trade it off and get what you need.