Ken- I bought a '71 Challenger V code about a year ago and have been learning about '71's ever since as my purchase had a lot of missing or incorrect details. What I've found is it seems there were changes going on throughout the year, and therefore certain things are hard to nail down.
An early build e body is not going to be the same as one built in May or June.
I still haven't figured out jack component detailing 100%. I'm pretty sure later cars the base and head were semi gloss black. Earlier cars, I'm not so sure. On '70's these components were dove gray. Perhaps there was a transition period, like early '71's were still gray, maybe at some point the heads were semi gloss black but the base was still dove gray? My car has a late October 70 SBD. I started out painting these items gray, but later decided they should be semi gloss black. I'm not at all certain at some point I won't be painting one or both items back to dove gray?
Jack hooks were dove gray, except a friend of mine with a late (June) build Challenger has a green (sort of a forest green) jack hook! He's owned the car since '73 and says that is what was in the car when he bought it. We spotted another late build '71 Challenger at a show last year that also had a green hook. He said that was the first time since hes had his car he has seen another green hook.
Cudas used a different jack hook, I don't know if any late cudas ever had a green one.
"Floyd" here on the board has been a great resource of info to me since I got my '71, he has an early build '71 Challenger and a '71 cuda with a spring if I recall, SBD.
And if I can help you out any way with your researching of your cuda, let me know, I'd be happy to compare notes with you!