Don't have any pics handy, maybe I can upload one later. I have a few spots where I bank hunt for divers and wanted to have a few blue bill blocks to drop in, but all mine where rigged for long lines. I was cleaning up after a season and thought i'd try something:
take a full length of decoy line (I use about 15' for all my floaters) and pass it through the hole on the keel (through it, not attached - like a texas rig). Attach a long line clip on one end and on the other your weight - I use keel grabbers with a length of shock cord.
I pull the top (or long line clip side) to about the lenght i want for long lines - a foot or two for me - then take that portion and clip and hold it with the same hand you will hold the keel or decoy then with your other hand wrap the rest of the line just as you would a normal floater. fold the long line tag back over and tuck it or clip it or however you want to leave it.
Now when you set the decoy - if its for long lines just free your leader and clip. If it's for floaters, free the leader, unwind your desired lenght and simply clip the leader to the anchor and your set. Workes with any type of decoy keel, depth notches or not.
It's a bit of a trick to figure out the wrapping of the line so that it doesnt come all loose when you free it, but wind it a couple times and you'll figure it out. I use 400# mono for all mine, not sure i'd try this with anything that could knot up real easily.