I'd be happy to help you. The listing agent and the buyers agent should be shown on the MLS listing. If you call me, 314-504-1131 or email me, email@example.com with the address, I'd be happy to look it up for you.
listing side is who represented the seller, selling side is who represented the buyer. The MLS, SHOULD be updated, but isn't always and it isn't always updated quickly, but that is the only place that the data is recorded. The other option is to ask your new neighbor.
Hi E.a. Bohn, That is a very easy piece of information for a Realtor to retrieve from the Multiple Listing Service. The listing firm and agent would be documented as a part of the listing which would reside in the Sold data.