Reminds me of touring Spain in '84, in a Citroen Traction Avant Commerciale.
After 7 weeks, up in the Picos de Europa, I was checking under he car. Saw a drip under the petrol tank; rubbed it with finger; it became a flow! Tank was rusty!
Quickly bought some chewing gum to seal hole!
Local garage blew out the tank with compressed air (and blew out the petrol pump diaphragm, I discovered later!), put some fibreglass filler on hole. Cost? £10. Got us home.
All in bad Spanish from me!