Retrofitting Captured Ships

[SgtBigG]

I recently captured two dreadnoughts which had psychic weapons. The weapons had been destroyed in battle. I then designed a new ship which had the same components as the captured ships and subbed in different weapons. Then I retrofitted the captured ships to the new design. The question is, is this cost effective? Would I be better off scrapping the captured ships and building new ones from hull up? Thanks.

G