FWIW, and JMO but Personally I have never seen a "Known Original" Holley 4053, 4346, 2818, 3246, 3247 etc., pre 1972 Holley carb that did not have the clutch head housing and screws. The later hsg with the Phillips screws shows up a lot on service dated or "restored" carbs from well known carb restoration company's for some reason. The early accelerator pump housings are very prone to bending/warping from over tightening as well as engine heat.
BTW I have been rebuilding/restoring carbs for 45 yrs., so I have seen lots.