There is a Record rear derailleur currently on eBay that has attracted many bids and perhaps a few from members of this list. It has 17 hours to go with a high bid currently of $250. This RD is said to be NOS, which it might well be; however, if you look closely, you will see that the rear cage is attached improperly. I believe that at the very least, the owner has taken the cage apart and re-attached it.
Just thought in case someone on this list wins the derailleur that you should switch the rear cage around before using it.
The eBay number is : 250185900705