I'd forgotten how you did that Norm ,I remembered some JB Weld was used ,did the JB Weld work well ?
I see no reason why the JB Weld would fail.

Looks like the vacuum pipe is cut off the intake on the cylinder and the plastic spigot slides over the hole.

https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/101221/lm-carby.html

I guess it shouldn't cost too much to pay someone to machine out the spigot if you don't have a lathe.

Cheers
Max.