you may be able to get things like the seals and screws at a local tool shop or something, i managed to find some grub screws recently at mine, hope it helps, if not you could always try america as they arent big bits adn so postage would b minimal
tried searching in the net at DIY stores but cant find anything, i can get a set of 6 barbs at fat bobs for £22 but dont wanna spend £22 and use one of them
are they going to be the same as the barbs on the standard cocker 3 way? if so i've got one you can have. not the tidiest but it'll work.
pm me your address if you want it and i'll stick it in the post