Carburetor Teardown - Help Requested

[anesde]

I successfully took off the carburetor and dismantled it, taking photos and labeling along the way uploadfromtaptalk1424653595614.jpg

My problem is the vacuum hose attachment. I took the hose off without a problem but this black plastic piece isn't coming loose. The manual doesn't mention it - I tried penetrating oil and needle nose pliers but no dice. Also tried needle nose vice grips but that didn't work either. Granted, I'm going with very light pressure so as to not damage anything

I wouldn't normally care about removing it but I'm going to dip all metal components and I'm afraid I'll damage this piece. Anyone have any suggestions?

Thanks in advance!uploadfromtaptalk1424654063850.jpg