This is intended to be a parts resource, including crossovers from other bikes.
Batteries: This guide by Wamey lists a few battery models that are similar in dimension and functonality to the stock Hawk battery.
http://www.chinariders.net/showthread.php?t=20893
TT250 - Hawk parts
One nice thing about the Hawk is that it does share a lot of small parts with the TT250. On top of that, many of these same parts are at least of the same quality, if not better, and much cheaper than new Hawk parts sold through other companies.
Link to TT250 Parts.
http://www.cscmotorcycles.com/TT250-OEM-PARTS-s/306.htm
Known parts crossovers include. Rear axle and nut, rear wheel seals, axle adjusters, all of the tank and side body panels, tail light and rear fender/license plate panel, Seat, rubber intake manifold, and even some accessories like the luggage rack. Some parts are a close match and require little extra work, such as the brake pedal, which only needs a small hole drilled for the brake light switch spring or the rear switch needs to be converted to a pressure switch banjo bolt.
Intake manifold to cylinder head gasket. 33.5mm x 3mm. Honda Part number: 91304-KRM-840
Brake Pads
EBC Part Numbers:
Front - FA086
Rear - FA165
Hawk 250 Starter Motor
Per Lit Hawk, he replaced his starter motor with one on ebay with the following specs.
Total length: 6"
Diameter: 2.7"
Mounting holes (center to center hole): 2"
Output gear: 11 spline