Not possible.The only way to reliably get in touch with motivated sellers is for you to make it easy for them to find you.Get a solid website, work on the 3 pillars of conversions:1.

During our conversation, I asked if they might be interested in selling the park.

I'm taking this season to dive into that, but wanted to start a conversation with those more experienced than me.

Wondering if anyone has a benchmark of #of calls-to-lead conversion rate for this activity? 

Yes, it is better to consolidate the 2 together, Google and Facebook at the same place due to the conversion you will see on your landing pages

Never throw your city into a conversation about another city.

We rent single family homes, so we have a conversation about yard maintenance, snow removal etc - have you don't this before, do you have the tools etcI also bring up house cleaning questions, by telling them we had a tenant who did not own a vacuum cleaner, did not know how to run a dishwasher, had a mess in the basement etc - and then see how they respond.That is a non-offensive way to talk about house cleaning and you'd be surprised how different the responses are.

@Theresa Hansen If you do some searching with keywords on here you will find loads of conversations with recommendations. 

But on the system it shows which lead called AND it recorded the conversation to replay!! 

These tend to be very comfortable, "Oh let me add you to my email list" conversations.