Well, you've had a lot of looks Bill and no replies, so I'll give it a go to give you something to think about. First the easy part. I believe the "nipple" is an outlet which comes in to play when the fuel pressure is excessive. From memory, it is too small for a hose to fit properly.
As for the screen, I have no idea why yours detached. Could it have been during removal from the tank? Mine was snug enough to give me no qualms, which is no help to you. All I can suggest is a strip of shim brass. Wind it round the tube and slide the screen over the brass. In anticipation of difficulty fitting the screen, make the strip twice as wide as the length of tube. That way, the screen might be easier to start on, over the strip.
You can tell i've never done this right?
Well, I hope someone Qualified comes along Soon ;-T
