Filler cap & breather pipe

Circle cutter. £3.50 eBay purchase, very useful tool to the collection.
Rubber gasket made to fit perfectly.
The tap eventually arrived, eBay pot luck with sellers dispatch time.
As I had set the position of the filler with the lid, I roughly marked where the breather would go.
Taking note where the locking cap fits and how much clearance is needed, you cant afford to allow the fitting to enter too far into the filler opening.

Breather fitting Supplied by GD. Tapered thread taped out with a 1/8 NPTF tap and Q size drill. I worked this out to be 8.6mm drill.
I remember Andy suggesting fitting a grub screw to stop anyone just undoing the filler lid and preventing it undoing during travel. Doubt it would but wont hurt. 3mm Grub.
Got 25' of 3/16" copper brake pipe from....... yes you guessed it, for £8 opposed to £18 from my local motor spares shop. For some reason I remember someone advising me to add a loop/trap to help stop fumes or spillage but will let it breathe. Plenty of room so why not. Someone can add a comment if there is any advantage to doing this as I can't quite remember.
I exited it out on the inside of the wheel arch as I would imagine if it went out behind the wheel (straight down), spray could find its way into the tank possibly.