Not only was the lug missing from my '66, but the remaining portion had been removed from frame. I bought a chopped frame from my local shop and cut the lug off. Actually, I cut the frame and had to machine out the center of the lug. I then split it, brazed it in place and welded up the seam.
Go to my restoration thread, Rob's '66 T120R and you'll see pictures of the process.
I think that the aftermarket lugs are way too much money for what you get. You could make your own and even duplicate the correct look if you have the tools.
But, if you don't want to weld, There was a replacement stand/lug made that was flat steel and u-bolted to the frame under the engine. One sold on ebay a few weeks ago and we talked about it here. You could make it yourself from a piece of 1/2" x 1-1/2" steel barstock cut to span the two frame tubes under the engine. Heat and bend one end to form the start of the lug section. Drill the flat section for two u-bolts. Then shape and drill the lug section and you are good to go.
Another thought I had is the Hinkley stands and bases are all over ebay for small bucks. I'd have to look more closely at a bike to see where you could mount it, but I would think you could make a mounting block that would clamp on and then both the Hinkley stand to. You might even be able to make the bolting of the stand to the block the clamping arrangment as well. Just a though.