Harold made them in 850,720,652,600,and 440 cfm . "His" carbs all carry signature like modifications and serial numbers. I have and have had many of his designs. Harold also did many of the "new" designs like the 428CJ carb and most all of the others.
Yes prototype carbs he made for Ford (EEE) would "usually" have an SK number tag on them but he also did work for the Autolite division where XF numbers were used. I have a few of them also.
Randy