Here is a real simple set up.

   I've been considering this, myself, for my sloop-rigged dory. I think there may be an advantage of the topping lift when you wish to raise the boom up against the mast in order to row.  I'm not sure if the lazy jacks will get it up very close to vertical. I have no experience here, so other comments are most welcome!

I've no experience with the NE Dory, but knocking about in a 19' catboat with a 270 sq. ft. sail might have taught me a bit about topping lifts and lazy jacks.  With a big sail like this on a boom nearly as long as the boat and heavy enough to actually go "boom," they are an absolute necessity, for sure.  On a NED with...what?...a 53 sq. ft. mainsail, I'm not so sure it is worth the complication and extra spaghetti, especially regarding the lazyjacks.

Looking at photos of sloop-rigged NED's in the gallery, it seems that some have the sail simply lashed to the mast, while others appear to have gone with some sort of track and slide arrangement with a halyard, allowing the sail to be hoisted past the forestay and shrouds.  I didn't spot any with arrangements for reefing.  The rig looks similar to the Alpha Beachcomber dories, probably not an accident.  I think with those, historically, the whole rig was pretty much set and left standing, sails and all, for racing and struck when not wanted, so nobody really cared about hoisting, reefing, etc.

With the NED's sail lashed to the mast, I assume furling the sail is accomplished by simply folding the boom up against the mast, right?  In that case, neither lazyjacks nor topping lift would be wanted, though you might want to rig up a sort of brailing line running from a padeye maybe halfway up the mast, down through a fairlead at a matching point along the boom, back up to a small block rigged opposite the padeye on the mast, thence down to a cleat.  That'd create some extra spaghetti, but it's simple enough that it might prove worth the trouble for quickly getting the mainsail and boom out of the way for rowing, providing there wasn't a snootful of wind blowing.

With the sail on a track and a halyard for hoisting, a simple topping lift might come in handy.  If there is enough of the mast sticking up above the head of the sail, and enough boom out beyond the clew, it'd be best to rig a single topping lift from the masthead to the boom end so that it won't matter which side the wind is on when hoisting or lowering and little chance of getting the sail hung up on the topping lift. That would at least take the weight of the boom in hoisting and prevent the boom from dropping down on everybody's heads when lowering, though it looks like a pretty light stick, to me.  In this case the drill in lowering would be to set up the topping lift, release the halyard, pull the luff of the sail down, quickly get a sail tie or two around the sail, then top the boom up as needed for rowing.

That help any?  Mind you, I've no experience with this particular rig beyond what I've read in Chapelle, et cetera, so I may not know what I'm talking about.  Hopefully, somebody with actual experience will chime in here.

.....Michael