The closest I've seen anyone come to finding/replicating the 2nd Doctor's sonic was this:
Gem Grading Pen Light
*WARNING! OrganicMechanic starts rambling in 3...2...1...
In truth though, I'm thinking that I need to go back and re-watch a few William Hartnell episodes. He used a pen light as well, albeit a different model-no sound-never called it a SS, in a way that makes me think of it as a sonic. If I can convince myself that it
could be a sonic screwdriver I think it'd make a great "extended emitter" version of Troughton's SS. We'll see. lol
But in that event, drawing up plans to combine the two would be rather simple.