so just found a puddle of fuel under the front of the panelvan today and after looking under ther found the fuel line dripping between where it comes out of the tank and goes to the hard line through the body.
there is a bit of a curve in it to get there and thats where the leak was.

here are a couple of pics showing the offending item after the cloth covering was removed and then a new piece thats never had fuel in it.
this fuel line was replaced when the car was restored 2 and a half years ago.
the markings on it are cohline 2122 then 0400 5.5 x 10.5 >ner

Tooley Imports 94762888 have a good quality fuel hose,ask for Richard and tell him what you need.

Anyone wanting a good quality 5.5mm ID hose then this stuff will easily do the job and a hose clip should still work on it too.

5.5mm ID hose

The cotton braided stuff may be the right size, and getting harder to source as very old skool size, but the rubber isn't formulated to handle modern day petrols so will perish fairly quickly.

While i understand that this hose comes in a 6mm size and not 5.5mm it is excellent, synthetic and normally available at good parts places of the roll, it will never split like shown in your photo.
https://www.powellindustrial.com.au/hoses-supplies/08-200-006-CUT_item.html?r...

Spec for the Ortac has an ID of 6.4mm, careful of the fit.

https://www.ebay.co.uk/itm/Honda-New-Engine-Bulk-Fuel-Line-Hose-5-5mm-x-3-000...

https://www.ebay.co.uk/itm/Honda-New-Engine-Bulk-Fuel-Line-Hose-5-5mm-x-8-000...

Easier source.

https://www.brickwerks.co.uk/fuel-hose-ethanol-bio-safe-5-5mm.html 

The cohline rubber couldn't have perished to that extent in that time. Maybe it was really OLD hose when (if?) replaced.

I/4 hose is fine with a good quality clamp.