I actually thought you would have known all the history on these.
1. 17 sets framed and given to key employees (not just available if they wanted them).
2. A further set was until recently on display at the Palm Beach Cannes. I dont know where they went although I was shown them (unless those are the ones you now have)
3. The set I sold was the cage managers set. Sold for under $3,000
4. The two odd ones you have - they also come in all denoms and there is a £25,000 (blue I think)
5. These do not date back to the Playboy era. The ones in use then were very similer but had two lines across the £ sign rather than one.
LCI never destroyed anything, in fact they have never obsoleted anything. That is why they had to drill them.
All the old stuff remains in the vault 20 foot beneath where the London Playboy is now.