Also known as the Crown.

The 1937 Crown was issued to mark the coronation of George IV. It was issued again in 1938 but collectors didn't take to it so it was discontinued. The 1938 year is now more collectable than the 1937 as the mintage figures are significantly less than that of the 1937. Good specimens of each of these coins are getting harder to find especially in UNC and higher grades.

The following is a guide on approximate values (in Aust Dollars):

The large fields on these coins will most likely have what they call in the industry, "detracting marks". These marks appeared during the handling processes at the mint. The coins would go along a conveyor belt after being freshly struck and then drop into a bucket. The coins dropping into the bucket would bump against each other and the edges would dig into the open fields.

Below are the 1937 and 1938 REV and one OBV which is the same on both coins:

Specs:

92.5% Silver & 7.5% Copper.
Reeded Edge
Weight: 28.27 grams
Size: 38.5mm

Source: Pocket Guide to Australian Coins and Backnotes 13th ed. by Greg McDonald.
Photos: From the personal collection of Asenath Amenhotep. The professional grading for each is as follows: 1937 --> UNC, 1938 --> aUNC.