That is like a bank robber asking for the keys for the bank rather than having to work hard at committing their crime.
Wouldn't it be better to find people that dont already have an annuity, especially considering most older annuities have much stronger contractual interest guarantees, much better mortality tables for lifetime income for themselves and beneficiary and most of all the surrender charge has expired. Your post could be the lead statement from the state regulator when they charge you with elder financial abuse.
Ignoring the privacy laws and violating the contractual privacy agreement with the client. Why on Earth would insurance carriers give that info away, just so agents could move the money over to another carrier?
When you see list services that talk about CD holder or annuity holder lists, they get that info from surveys were people check a box saying if they own this product or not. And usually those lists are worth the paper they're printed on.