I've got a spare set of fuel lines somewhere, ends are rusty like all but they haven't been full of fuel for 40+years! The fittings I think are BSP, standard copper gas pipe fittings for 8mm should fit the fuel sender unit and reserve tap should you decide to research alternatives?
I'm not a fan of regular rubber fuel lines anymore, they have a habit of perishing and going hard after a couple of years. Really high quality rubber hose should last a lot longer, can't recommend a source or spec myself. I'm soon going to be replacing the fuel lines in my P6 with braided teflon hoses and Aeroquip style fittings, should hopefully last a long time once done!