when i bought my used 50th anniversary hummingbird, the shop provided a dunlop pick, this one: https://www.jimdunlop.com/celluloid-shell-pick-heavy/
and i found that it brings the honey feel you talk about... i found that celluloid is the equivalent of my real tortoise shell on my electric, the best pick you can dream about...
i tried other "plastic" pick but they don't sound the same, cheaper...
the heavy size is cool when you need to force a little on the strings, but to be honest i use one of the two round sides instead of the sharp one to get the mellow-ness..
so you know, i use PB d'addario EJ16 or EXP16, i hate 80/20 on my Hummingbird... loose the hummy sound...
Ben