+1 Simba, but please everyone be VERY VERY careful with MEK while its a good solvent it will immediately and permanently blind you if you get it in your eyes. Yes it is also a known carcinogenetic so gloves is also highly recommended.1. ABS powder from Ebay mixed overnight in a glass jar with MEK forms a nice thick ABS slurry. Then, apply to form shape. There are tutorials everywhere. here are black pellets: 6 pounds of pellets (should last a lifetime) for $22 http://www.ebay.com/itm/ABS-PLASTIC-PELLETS-6-lbs-BLACK-COLOR-FOR-MAKING-SLURRY-TO-REPAIR-ABS-/330978602679?pt=LH_DefaultDomain_0&hash=item4d0fdcaeb7. Other colors available. MEK can be obtained at any hardware/Home Depot/ Lowes/ Menards, etc. You will need a glass jar with a lid as the MEK (or acetone) is nasty and possibly carcinogenic. Use it outdoors and don't breath the fumes.
2. You can also go to any body shop and request a free section of ABS bumper. They usually throw them away. Then cut the ABS bumper to the size tab piece you need. Sand off all the paint on the edges. Then, apply plastic welding to attach the piece you cut to the fairing piece. There are tutorials in plastic welding on the net. You have to reinforce the plastic welded piece with ABS cement or ABS powder slurry mix with MEK to get a strong bond.
3. Plastex that LeDude used works excellent. I am sure he will have a tutorial. LeDude you have saved me $$. It would be an honor to buy you and yours lunch.