Ken-
Diamond Jubilee frames are just another marketing variation, like the "Barcelona" I have, its all in the transfers, and or paint of which I happen to like the over the top "Greek" & flag extravaganza.
The Special on ebay thankfully is too large for me, I have made a number of purchases from this seller, including a bike, and he tries hard to do a good job.
John Jorgensen
Torrance Ca