Where to start checking for clogged fuel tank breather?

Noticed some fuel leaking from around the filler cap, even after the car was sitting a while.

There's also been some issues starting - doesn't catch for while and feels like I have to prime the fuel lines a few times.

Googling has lead me to believe this could be due to a clogged breather pipe. Could this be it, and if so where should I start looking (is there a breather under the rear wheel arch?)?

Hoping to hear your opinions.

('93 1.8lt injected Cabby)

I would start at the Vent line near the cap. and the gravity valve first.