M500BY

probably one of the more trivial parts reqired. the latch on the inside of my fuel filler flap (try saying that fast after a few) has decided to break and fall off. on going so subaru to purchase this part, i'm told that it actually comes attached to the flap. cost £36 + vat, with the cost of painting to go on top of that. on closer inspection of the broken part(not salvageable) it looks as though the clip slides onto the inside of the flap. does anyone have one of these, or able to confirm where i can get 1, or will i have to scour for a 2nd hand flap. car is a 1998 wrx.
any help to the above appreciated.
thanks martin