Bob, option IV. Do not paint it. Unless there is major repairs to be made on the deck and hullsides, don't do it.
PRESERVE IT, don't restore it. You have an amazing boat. Clean it up, and enjoy it for what it is. I took a Silver at Keels and Wheels this year with mine, and I fully believe it was because it is unrestored. Lots of scratches, dings,etc. I take lots of pride in those blemishes, it means my boat has done it's job over the forty years of it's life: it was used and made people smile!
Grumble Green is a somewhat rare color. I'd preserve it as best you can. The gel on the old Donzi's is VERY thick, and will buff out beautifully. Find someone who knows his way around a buffer, (maybe it's you?), use 3M buffing compund and a good wheel, and let fly! You'll be shocked!
1970 18 2+3 Hull #18-355 H/M 351W Volvo 250
07 Cayman IT IS BACK! - '13 Abarth Cabrio
PRESERVE, DON'T RESTORE