No luck yet. About one year ago I was talking to Teddy Scout about one that he was willing to sell to me. However, after a couple of emails he stopped replying and I was never able to contact him again.
I must have sent at least 20 reminders but no luck. Although a vertical louver version will fit the muffler, I insist on a horizontal one for 'historical correctness'. Not sure if the regular one is incorrect (I have seen sand cast mufflers with the vertical cover) but somehow I feel that the horizontal one was the original part?
Also, I forgot to mention it earlier but impressive work you did with reproduction of those 'G' specific parts. At first glance I thought the reproduced part was the original. That is quite a handy talent you have. Could you also (theoretically) do it for even older Stihl (two man saw) parts like the top and bottom ends of this (left) muffler type?
I was also wondering about the cylinder in the ebay auction you posted. Probably not original but somehow the mounting in the case shown there also look odd. I don't have an 090 apart now so I cannot check if it's really different.