About to quit my startup job. Advice?

About to quit my startup job that is equity based. These people are clowns. I have only vested about half of potential shares. I have my contracts: services agreement, statement of services, share vesting plan. I have downloaded emails and forwarded emails (gmail server) providing proof of dates and that they were delighted with my performance at work. Is there anything else I should retain in case they try not to honor my shares? Should I ask for a lawyer as a contact point? What's the procedure here? Sorry, I'm pretty green. Are emails enough?