I have an unsolicited offer from Tantor Audio to purchase the audio rights to my romantic suspens...

I have an unsolicited offer from Tantor Audio to purchase the audio rights to my romantic suspense trilogy. I negotiated oil and gas deals for a living for 32 years, and I know enough to know I don't know what I'm doing negotiating in this industry. Does anyone have or know of an agent that might be willing to handle this one deal for me? It’s not a large sum of money, but it is rights for the whole series. (My books are self-published, so it’s just this one deal.) Thanks.