On a side note, I bought a pair of NS-500M tweeters that were advertised on ebay as NS-1000 tweeters. (Another ebay ripoff but I am over that now.) The Be dome is the same size as the NS-1000M's JA-0513 and the magnet appears to be the same so I went ahead and installed it. As far as I can tell, they sound the same.
The size of the flange is slightly bigger so I had to rout the opening slightly to fit the JA-0544 tweeter into the 1000 cabinet. Also, the face of the flange is crowned and machined on the JA-0544 while the JA-0513 is flat. Because of these differences, I do not recommend using the 500M tweeter in the 1000M.