I've got a couple of the old Revell kits and started on one years ago. Made a bunch of the interior cabin frames to add detail and didn't get much further. It needs a lot of work to make it into a decent "Jolly Green". I found some pictures at
www.jollygreen.org I never did pick up Squadron's In Action Book on the CH/MH-53 so I don't know if there are any good references. It's a shame good kits of the CH/HH-3 and 53 Jolly Greens haven't been made after all the lives they saved. It's odd that the helicopters that were the workhorses of the Vietnam War don't have "good quality" 1/48 or 1/32 kits of them, the UH-1D/H, CH-3, and CH-53. The "Hooks" are coming! Where are the "Jolly Greens"?