Jaime Hernandez:
From 1950-1958 proof coins with cameo or deep cameo surfaces are difficult to acquire. Most examples displaying cameo or deep cameo surfaces have probably already been pulled from proof sets and submitted to be graded, since most coins with cameo or deep cameo surfaces command significant premiums.
The 1955 Proof Lincoln cent is uncommon with cameo surfaces and considered really scarce with deep cameo surfaces. Even though it is the easiest proof Lincoln cent from 1950-1958 to find with cameo and deep cameo surfaces, it is still a very tough coin as the majority of the mintage display red without displaying cameo or deep cameo surfaces.