Carb rebuild kit number

It is a 4 digit number with letter after it sometimes, and may have 'R-' in front of it. Look for a flat area on the body with stamped number inset in the metal; raised letters are not the list number.

In this photo of an early Holley 1920, it is on the flat area on the right hand side in this pix by the idle screws. On some other 1920's, it is on a flat area on the opposite side. (Sorry , I could not get this rotated for some dumb reason....)