I think the best messaging is "Proof of concept" that is, you talk to an investor and tell them: "We've done this before, it worked, we know the playbook, now we're raising money to go do it again"
As far as meeting investors, it's tough. People want to invest their money with people they know and trust. Your friends and family are a good place to start. It may feel... dishonest to ask them for money, but remember your goal is to MAKE them MORE money.
I would try to grow your investor list organically. Start with friends and family, ask if they know anyone who might be interested. Try to meet with those people, then ask if THEY know anyone who might be interested. Follow the path wherever it leads. At first, you don't need many investors. Two, three, maybe 5 will do it. Then build the momentum from there
Going to networking events and meetups can work, especially if those people are already looking to invest their money, but it's all about relationships and it's hard to build a great relationship with someone you just met at a meetup. It takes time.
Hope that helps! Best of luck!