This is a interesting record that i found on a web site. This lists players who played only one test match and either scored a Century or took 5 wickets in an inning. I wonder why were they dropped then? 
Ashley, W H (SA) - 7/95
Carr, D W (ENG) - 5/146 & 2/136
Ferris, J J (ENg) - 6/54 & 7/37 
Ganteaume, A G (WI) - 112 & DNB
Malone, M F (AUS) - 5/63 & 1/14
Marriott, C S (END) - 5/37 & 6/59
Redmond, R E (NZ) - 107 & 56
Smith, C A (ENG) - 5/19 & 3/42
Warren, A (ENG) - 5/57 & 1/56