Fuel lines from body to engine (size??)

[elfhearse]

I have a slight fuel seep from the rubber fuel pressure line (with plastic braided cover) the runs from the steel fuel lines ahead of the fuel filter and transitions to the steel fuel line that connects to the injector rail below intake manifold.
This line is not shown on the bmwfans OR realoem parts breakdown, so I "assume" it is a standard rubber fuel line that can be purchased locally.

Anyone know the size of the rubber hose? (don't have time to rip into it this weekend, heading to Carlisle Import show) Thanks

FWIW: Symptom - car cranks for about 3-4 seconds before starting if sitting overnight (fuel pressure bleeds down from the seep) Starts OK if it's been setting for a short time.