I m not a user of this bike
But chian sprocket set of 70/100/qingqi can be tried I am sure it will be using same hub so may sprocket set should work.
For body parts you would have to find shops in your locality.
Chinese imports always suffer body parts availability issue.
I am using Piaggio and couldn't find its body parts like meter, fenders, side covers, seat cowling.
That's genuine issue of Chinese imports. Always ruined by body parts.
Regarding sounds in second gear, second gear sprocket might have gone bad due to improper gear shifts or clutch settings.
And would require splitting apart its crankcase. Which would involve 100-1500 rs mazdori and further 300-500 for only replacing second gear sprockets. Ilor 1200 rs for complete replacement of gearbox. Kisi bhi 70/100/110/qingqi ka lag Jaya GA complete gearbox. You would also need 200-300 for jain kit. (gaskets etc).