Can't answer your question ..... but some info on these varieties ....... some interesting reading on breeding on this site
Prime Beefsteak (Hybrid no. 3) – Breeder and vendor: Ferry-Morse Seed Co. Parentage: Ferry-Morse inbreds. Characteristics: F1 hybrid, midseason, very large globe-fruited tomato with green shoulder and excellent ripe flavor, intended for market gardens, plant growers and home gardens, vine is medium large. Resistance: verticillium and fusarium wilt. Similar: Unique. Adaptation: western, midwestern and eastern United States. 1974.
Wonder Boy – Breeder: Petoseed Co., Saticoy, Calif. Characteristics: F1 hybrid, midseason cultivar with indeterminate vine; fruit very large: 1 pound or more. Adaptation: midwestern, eastern and southern United States. The Peto Story, Petoseed Co. 1959.
Wonder Boy VFN – Breeder and vendor: Petoseed. Characteristics: F1 hybrid, large fruited, smooth, deep oblate to globe shape, green shoulders. Resistance: verticillium, fusarium, and root-knot nematodes. Similar: Wonder Boy VF. Adaptation: wide. 1976.
http://cucurbitbreeding.com/todd-weh...ca/tomato-j-r/