At the top silicone (fuel resistant)90 degree bend all are 51mm
http://www.ebay.co.uk/itm/Blue-Silic...cAAOSwuAVWyZaN
90 degree tight stainless bend
https://www.ebay.co.uk/itm/90-Degree.../263164672353?
epid=864132173&hash=item3d45d63961:g:ZA0AAOSwa39Uy hRF
Long 90 stainless than is pushed and glued into the existing filler pipe.
https://www.ebay.co.uk/itm/2-51mm-90...MAAOSw~gRVywsv
If you hunt on my build thread you will see what adhesive I used. Make sure there is half a tank of petrol as you will need to leave it for a few days to go off.
Happy to help with the fitting.
My anti glug was just a piece of fuel line fitted to the existing with a bayonette conector (same as on the washer line and fitted to the new top elbow.