Punto cabrio fuel leak

[david.h]

We have had our 1997 Mk1 Punto Cabrio from new and it has now covered about 70000 miles, mostly local, but some proper journeys. It has been remarkably reliable with only routine maintenance and replacements. Suddenly it developed a fuel leak that manifested itself by petrol appearing at the forward edge of the offside rear wheel after a fill up. I thought it might be overfilling, but it continued to drip as miles went on. As the fuel was used up the leak reduced and now with 2/3 tank it has stopped.
Access to this area looks difficult I don’t think it is from the tank, but from the quite complex fuel lines.
Anyone heard of this? Is the tank/fuel line/overflow unique to the 176 cabrio?
I’m planning a trip to Bavaria in September, so need to get it sorted. I doubt replacement pipes are thick on the ground
Any ideas? Or know a good Indy who may be familiar with this model in the Midlands ( I’m near Stratford)