The majority of the 1973 quarters were struck with a modified obverse featuring a smaller portrait of Queen Elizabeth II. This Small Bust obverse allowed for better metal flow during the minting process, ensuring the fine details of the reverse design were accurately rendered. Along with the smaller bust, the number of beads around the obverse was reduced from 132 to 120, and the beads were positioned slightly farther from the rim. This adjustment also provided a more refined depiction of the Queen's hair detail.

A rare variation, known as the Large Bust, was created when fewer than 10,000 quarters were mistakenly struck with the 1972 obverse die. This die featured the larger bust of Queen Elizabeth II with 132 beads. The Large Bust quarters are distinguished by the proximity of the beads to the rim—almost touching—and the position of the apex of the letter "A" in "REGINA," which points directly at a bead. In contrast, on the Small Bust variety, the apex points between two beads. 

The 1973 Large Bust quarters are highly coveted by collectors due to their rarity and the unique circumstances of their creation. These quarters, with their less common obverse design, often command higher prices in the numismatic market compared to their Small Bust counterparts. Collectors value both varieties for their historical significance and the craftsmanship involved in their production. 

The 1973 Canadian Quarters, with their Small Bust and Large Bust varieties, offer a compelling study in numismatic history and minting processes. The commemorative design celebrating the RCMP centennial, combined with the obverse variations, make these quarters a prized addition to any collection. For collectors and enthusiasts, the 1973 Canadian Quarters not only represent a significant piece of Canadian history but also highlight the intricate artistry and technical challenges of coin production.