CWC serial number suffixes are often stamped lightly and easy to miss or misread, Your second number is probably F60481 ACw. The ACw suffixes followed the Cw series and ran through the same letter sequences for the initial letter. My data puts this bike's production around the end of 1950 or the beginning of 1951. Between the first frame and this one the rear dropout stampings were changed. Another difference between the earlier and later bike would be that the first bike would have used straight truss rods and the later bike would have been originally equipped with the bumper style that project out to the sides.