During the 13-year run of the Crass Model there was a lot of variation in the engraving patterns as the Ithaca Hammerless grade structure evolved. Some of the earliest No. 4 were not very fancy, then they got very elaborate and into the upper 2xxxx range they settled into this style. The No. 4E with the engraving attributed to Robert Runge is 29880, two digits after the RIA gun linked above.
I don't know the serial number of this No. 4 Crass picture I saved --
CRASS No. 4 12-GAUGE, 30-inch great dog.jpg