Rich and Steve tank question

[Jon G]

When you guys had your gas tanks made do they need the old tank or do you give them the measurements? I'll be pulling mine in a couple of weeks and don't know what I'll find, boats a 74' and was told tank was origional, hoses look ancient at the fill/vent were I can see them. Topped it off for the winter and four days later bilge reeked of gas, no liquid though. I pulled a couple of gallons out and it went away probably a hose or sender but if the tank is origional I want to replace it, its trying to tell me something, better now then next spring.