These OCC stingrays can be a pain to build, but I think it is worth it in the end because they are just so unique. I think the wheel is a 36 spoke but I am not sure, I would have to count them. If it where me, I would try drilling the holes on the sprocket one size bigger with a drillbit, and then see if the bolts would go in then. If that doesn't work maybe you could try drilling 5 evenly spaced holes closer to the center that would line up with the hub then bolt it to the hub. If you do that, try not to drill too close to the spokes because they could break. I first built my bike in 2005 with a 48cc kit and the 1 gallon tank came with the kit. But in August 2008, I upgraded to a 66cc engine, and the tank in that kit was only 1/2 gallon, so I kept the old one on. I painted the tank, it was originally black. You might be able to find a motorcycle tank on ebay or a tank like mine to use instead of the kit tank. The sprocket from my first kit fit, I just drilled into hub and bolted it to the hub. The sprocket in the second kit did not fit because the holes were further from the center and if I remember correctly, they did not line up just like you are saying that yours doesn't, so I kept the first sprocket on it. Here is a picture of the bike when it was first completed in 2005, and some others with the most recent paint job on the tank. Towards the bottom of the gas tank I hand painted my initials but you can't really see it in the pictures.