Thanks Tom
As always
I was poking around and found the stock carb for the OS Sirius available. It would be a direct fit if the invert diameter is correct. Trying to get that data from HH. I don't have access to machine tools and my Sirius fr300 runs so sweet with it's oem carb. I am hoping the new design will be as good as the previous, even better.
And will not need adaptation to mount on the old German Beauty.

Aaron-