Bowman Heritage 2001 - Bowman 1948
Bowman Heritage 2002 - Bowman 1954
Bowman Heritage 2003 - Bowman 1956 prototypes
Bowman Heritage 2004 - Bowman 1955
Bowman Heritage 2005 - Bowman 1951
There isn't any sort of consistency or pattern. Topps just seems to randomly pick a Bowman year for the Heritage design.
The 2005 set has 350 cards with the last 50 being short-printed. The Cubs have ten veterans and four rookies / prospects,