Haven't seen pics of the car but but it's worth $35K+ if in nice shape. As a coupe, high $30s, low $40s.
This happened to me recently on a 240Z with 30K original miles. I saw within an hour of CL posting but decided to wait until the morning. The seller let me know someone else had emailed and he had first crack, I was next. For $13K, I knew the first guy was going to get it. I appreciated that the seller wanted to let the first guy who contacted him look at it first.
I think you did the right thing. If you agreed to let the guy see it at 7:30 then he's first in line. But at 7:31 with no phone call/email/text, all bets are off.
Post the CL ad.