If the pump is by the fuel tank it's a pusher type, which are pretty easy to get hold off. The big question is what flow rate and pressure is required? If it's got carbs, then you need a low pressure type, but if it's injection, then it's going to depend on the injection system.
What engine has it got in it? If you look at the Burton Power website, they have loads of fuel pumps for both carb and injection engines, in the £30 - £130 range.
