I am not sure if you need this for an antibody produced by human B cells, or mouse, rabbit, or some other organism. I am not an expert on this, but our HIV Immunology database has links to tools that are useful for studying human antibody development. The list is here:
Also, I am not quite sure what you have now for an antibody sequence vs what you need to know about the regions which would be used to create an scFv recombinant. https://blog.addgene.org/antibodies-101-single-chain-fragment-variables-scfvs