welcome. thank you for doing for your husband what he is not able, ready and willing to do for himself at this time. any information and insignts you gain will be helpful, i am sure - and there is an abundand\ce of that here.
i too was abused by a step-father - starting at 5 1/2 with the physical/sexual part continuing till age 13 and the verbal/emotional part going on until i left home at 18. so i am familiar with that dynamic. i also was "adopted"by the perp - so i have his last name. i would love to have shed that years ago - but it just would have caused more problems with my mom and having to explain to others - so i just resigned myself to it. it might be a good thing in your family's situation to consider - but it will have to be with his agreement of course. there is something empowering and transforming about changing one's name - you see lots of that in myths, fairy tales and the bible - a concept that many people acknowledge.
sorry to ramble on - but your PS caught my attention.
hoping that your H will soon be up to facing and dealing with his past. it is worth the effort.
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"