Diving Dolphins made made for a long while (on and off for 60 years or so) but I don't think Rosalin (pink) was introduced until the 1930s (33?). What you have is probably about that sort of date.
A so called straw mark (totally misnamed) is probably a shear mark. It forms when the gob of glass is cut off with (cooler) shears and dropped into the mould. It's not damage, just an indicator of semi-automatic or even hand pressing