I have a 20 bore non-ejector. 115xxx. How can I tell which model?

Post pictures, post a description,post distinct features.

M300 ?

IDK, I don't know what features make up the difference in models.

It appears to be a Model 600. By the serial # it was made in 1936. In the published book, "The History of W. & C. Scott Gunmakers by Crawford and Whatley, pg. 69, it shows an illustration of your shotgun with a brief description. It states the shotgun was made in 5 versions from 1927 to 1946. "The Model 600 (Figure 62) was introduced in 1927 as a non-ejector gun in plain quality only. Webley & Scott supplied the Model 600 in 12, 16, 20 and .410 bores; most guns were made without a rib extension. A number of versions, including the 601 (1937), 602 (1937), 603 (1938) and 604 (1939) were added to the series before production ended in 1946."

Thank Tim

The Model 300 looks similar to the Model 600, but has the Greener crossbolt. In 1939 the M300 was replaced with the Model 300A which had more engraving, and it was produced until 1946.