Welcome to the forums
That's a unique looking hardtop...I'd like to see more pictures of it.
Your vibration could be caused by any number of things, but a good place to start would be the wheels. Inspect tires and replace any that need replaced, then have the wheels balanced.
I'm not sure what an AC refill would cost in your area, but you should have the entire system inspected while you're at it.
FYI: It's not uncommon to have a leak(s) at the condenser coil or plumbing under the front bumper from curb scrapes.