I'm in the same boat. My LBS can order the Sugino chainring, but it's out of stock. What's worse is that I'm also trying to find the same thing in black to match my black RDs. That is impossible. Luckily, I'm willing to accept either 48t or 52t, so I can find road rings that fit and just ignore the ramps and pins. Actually, I have a black 48t FSA chainring, but I'm still half-heartedly searching for something a little more plain.
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Reason is a scoundrel, stupidity is direct and honest. –Ivan Fyodorovich Karamazov
Man's mind, once stretched by a new idea, never regains its original dimensions. –Oliver Wendell Holmes