'66 273 BBD Carb

Sorry for my ignorance on this but what are those holes for? Idle mixture screws look intact. Is it just a bleed hole? Or a clean out hole plugged from manufacture passage drilling? If so - any good tig welder could weld that up in a flash for you. A dab of weld and flush it off and done. Again- not knowing what it is for as in 40 years of rebuilding carbs I’ve yet to see that. good luck and let us know how you make out.