Originally Posted by gugie

The question is what do you do about it if it isn't brazed on? It appears that it's just the front edge of the bottom lug. The critical part of the braze is at the junction of the head and down tube. As a mental experiment, what would happen if that little lip part of the lug wasn't there?

As long as the head tube isn't cracked, I'd let it be.

@repechage has good eyes. I looked again and it does appear that the bottom headset cup isn't pressed all the way in.