Given Localbitcoins and probably Paxful, too, will retain all account information for five years after account deletion anyway, it would probably be a good idea to copy users' reputation over into nostr events to more easily bootstrap trust in a decentralized protocol.
Users could set their homepage to something containing their npub on these platforms and multiple non-colluding accounts could run a script to attest to these accounts having that reputation and being this npub on nostr.